Popular games for platform Sinclair ZX81

Fortress of Zorlac is a shoot 'em up with some similarities to Yars' Revenge. The player's objective is to rid the galaxy of a dreaded alien called Zorlac. Zorlac is positioned on the right side of the screen and is protected by a fortress consisting of three rotating walls as well as four indestructible stationary guns. The player starts out at the left edge of the screen but can move around in all directions. To be able to hit the alien the player first has to blast a hole through the three walls. It is made harder by the constant movements of both the rotating walls and the alien. At the same time the player has to avoid being hit by the defense guns which automatically lock in on the player ship. As the game goes on the fortress slowly moves toward the player who gets less space to dodge the enemy fire. Once the player has been able to hit Zorloc, he gets enraged and the game moves on to the next level that's played at a higher speed. The player scores points by destroying the walls of the fortress and for hitting the alien. Points are awarded based on the skill level chosen before a game and the player's distance from the edge of the screen. Hitting the alien is worth fifty times more than destroying a block in the fortress. The player has access to five ships and once they have all been destroyed the game ends.

Byter is a Pac-Man clone. You control a mouse, moving about a maze and attempting to eat all the dots while avoiding monsters. If you touch a monster then you lose one of three lives but if you collect one of four dollar signs then you can eat the monsters for a short time.

Munchees is a Pac-Man clone where you must move around a maze to clear it by eating all the dots. As you eat the dots you have to avoid ghosts and if you touch one then you lose one of three lives. There are power-pills that can be eaten and these allow you to eat the ghosts for a short time. You have a choice of how many ghosts on the maze (1-4).

QS Scramble is a clone of the arcade game Scramble. It's a side-scrolling shooter where the player controls a space craft flying over the surface of an alien planet. Movement is limited to moving up and down and there are two weapons to attack with: forward going missiles and bombs that are dropped onto ground targets. Five missiles can be fired at a time and three bombs can be dropped at a time. Targets include aliens that swoop down from above and rockets that launch from the ground. On the ground there are also fuel dumps. The game goes on until the player has lost all three lives or the fuel runs out.

Namtir Raiders is a fixed screen shoot 'em up. The objective is simply to shoot down as many enemy raiders as possible and save the earth. There are four waves of enemies and each wave has a different kind of enemy. The movement of the ship is a bit different from other shoot 'em ups. Rather than having keys for up, down, left and right, they here lead to diagonal moves (for example up and left, down and right). The player has five lives and earns more when all four waves have been completed. Once they have the game starts over with the first wave. A difficulty level between one and three can be chosen before the game begins. The higher levels run at a higher pace.

QS Asteroids is a fairly basic conversion of the original arcade game. The action starts immediately after loading (no title or options screens here) and players finds themselves in a space ship in the middle of the screen with numerous asteroids passing by. To control the ship, two keys are used for rotating it, one for shooting and another for thrusting it forward. Shooting can be done in eight directions. On an unmodified ZX81, the ship is represented by a number which changes with rotation (For example 0 means it's pointing up, while 4 is down) and the asteroids are o's, while users with a QS CHRS board get graphics more similar to the arcade original. The player starts with three ships and after 10,000 points a bonus ship is given. Asteroids appear in waves. The first one has two large ones and the number increases with each new wave.

Pac Rabbit is a Pac-Man clone where you take the role of a rabbit and you move about a maze eating all the dots to clear the maze. As you eat the dots you must avoid the hounds that are hunting you but you can eat magic carrots which enable you to eat the hounds for a short time. If you touch a hound then you lose one of ten lives. There are six mazes split into two parts, Rabbits Revenge and Run Rabbit Run and you can choose the speed of the game (0-9) with zero being the fastest.

10 Games is a collection of games and programs on one tape. The collection contains: Klingons: You are a spaceship returning from a mining expedition and you have run into a Battlefleet of Klingons but you have no guns so with your shield you must ram them all. The game is viewed from above with you scrolling down the screen and the Klingons scrolling upwards. You receive extra points for any Battleships or Motherships that you hit. Crash-Landing: Your spaceship has been hit by a meteor and you are prepared for a crash landing on a planet with the only control you have is using your rockets. The game is text only and you see your fuel levels, velocity, height and the time. Simon: Based on the classic game where the computer shows you a sequence of colours and you have to input the same sequence. Every time you get the sequence correct, the computer adds another colour to the same sequence. Artist: A drawing program that allows you to draw pictures and shapes on the screen with a cursor. UFO: A row of UFO's sit on the top of the screen and your spaceship scrolls from the left of the screen below them, firing one shot at a time to remove parts of the UFO's. Every time you hit a UFO you score a point and you start scrolling from the left of the screen again. Missing a UFO or hitting the right side of the screen loses you points. Code: Based on the game Mastermind, the computer thinks of a 4 digit number and you have to guess it within a set number of guesses. Once you enter a number the computer tells you which number is correct in the right place and which number is correct in the wrong place. Asteroids: Your spaceship has hit an asteroid field and like the game Klingons you have no gun but instead of ramming the asteroids you must avoid them for as long as possible. Bomber: The game is viewed from the side as you watch a Bomber fly from left to right across the screen. The land is below with a dam on it and you must drop a bomb to hit the dam. Each dam that you see appears in a different location. Kaleidescope: This is program based on the toy where you see dots moving about the screen making symmetrical shapes. There is no interaction from the player. Guillotine: A two player game based on the pen and paper game Hangman but instead of saving your self from being hanged you must stop yourself from getting your head chopped off by a Guillotine. Player One enters a word and Player two has to type in letters to guess the word. Get a letter right and it appears in the word but get it wrong and a Guillotine starts to appear.

2K Games Pack is a collection of six games and programs. The collection consists of: Snail: You have $50 and the choice to bet an amount of money on one of four snails to reach the other side of the screen first. Advice: A program which gives you a statement to take as advice. Dice: You and the computer take it in turns to throw a dice and the winner is the one with the highest score after 10 throws. 31: The computer gives you a number and you decide whether to receive another one with the aim to get closer to 31 than the computer. Sketch: A program allowing you to draw pictures and shapes with a cursor. Reverse: A puzzle game where you have to put 10 mixed up numbers in order by selecting how many numbers from the left will be reversed.

Asteroids (Software Farm) is a clone of the Arcade version which sees your craft in the middle of an asteroid field and you must destroy all the asteroids to survive. The asteroids start off large and when you shoot one then it splits into two, and shooting an asteroid this size splits it into two again before being destroyed with another shot. Occasionally an alien craft appears moving across the screen and this can be destroyed for extra points. If you are hit by an asteroid or the alien craft then you lose one of three lives. You are able to turn your ship 360 degrees as well as move forward. There are three skill levels (1-3) and four players can play with each player taking it in turn when the last player is killed.

Airline is an economic strategy game, with the player taking the role of a Chairman for L-AIR, an air company whose business starts off with £3 million. He has 7 years to increase his net assets to £30 million. The player can charter, buy or sell aircraft, as well as managing staffing, maintenance and insurance. Situations in game (like hijacks, air crashes and sabotage) and costs (of fuel and aircrafts, tax demands etc.) are realistic. The graphics are simplified, made ​​up almost entirely of tables and texts.

Bat Cage is an action game where the player has to capture bats while fighting off other bats that try to rescue them. The playing field consists of a bat cage in the bottom and above it a bat flap around and there are also eight bat eggs bouncing around. The player controls a bar that can be moved around freely. It is used to capture the bat eggs which are taken to the bat cage where they can hatch. As soon as the hatching begins the bat at the top of the screen will attack and try to rescue the egg. The player then has to use the bar to fend it off. It works a bit similar to Breakout as the bat will bounce back up again when it makes contact with the bar. The player then scores points as long as the egg hatches. Ultimately the attacking bat will give up and retreat and the player can move on to the next egg that needs to be captured. As the game goes on the player will reach bonus levels and the number of attacking bats will increase. The game is over when the bats stay at the top of the screen and no longer attack when the player hatches his eggs. The game can be set to different skill levels (1-36) that alters the speed of the game.

Breakout 3 is based on the arcade game Breakout but instead of the bat on the bottom of the screen, the bat is on the left side of the screen. The aim is to hit bricks on the right of the screen to make them disappear but if you let the ball past the bat then you lose one of three lives. Before the start of the game you can choose whether to play with one or two bats, and playing with two bats has them parallel to each other a small distance apart. There are also three types of games to play and they are: Practise Game: A normal game with the choice to choose the speed of the bat (1-4) with 1 being the slowest. Progressive Game: Every time you hit the ball it speeds up and also removing a set of bricks makes the ball faster. Acceleration Game: The ball will speed up for every 10th brick disappearing and it speeds up when all the bricks have been removed.

J.D. Arcades is a collection of three games that contains: UXB: You have to move around a maze to catch four tumblers, which are numbered and must be collected in the correct order. Once you have collected them all then you must get to the detonator before a fuse reaches it. If you collect the wrong tumbler or hit the fuse then it is game over. Strategic Invaders: A Space Invaders clone where you control a base moving left or right, blasting aliens who are above in formation, moving across the screen, slowly descending downwards dropping bombs. Between your base and the aliens are shields which lose parts every time you hit one or the aliens do. One unique feature is that each position on the screen your base is on, only has nine shots. It is game over if you get hit by an aliens bomb or you allow them to land. Laser Patrol: A side view shooter where you must move a spacecraft up or down to either avoid or blast asteroids that move across the screen from right to left. if you hit an asteroid then it is game over.

Asteroids (Silversoft) is a clone of the Arcade version which sees your craft in the middle of an asteroid field and you must destroy all the asteroids to survive. The asteroids start off large and when you shoot one then it splits into two, and shooting an asteroid this size splits it into two again before being destroyed with another shot. Occasionally an alien craft appears moving across the screen and this can be destroyed for extra points. If you are hit by an asteroid or the alien craft then you lose one of three lives. You are able to turn your ship 360 degrees as well as move forward.

A maze game made by Jeff Minter from Llamasoft. The maze was a cube, and you could go through holes in the floor and ceiling as well as left and right

Kids TV favourite Postman Pat aims to stamp his authority on the games scene by delivering a first-class licensed game. Your job is to guide Pat and his van around a particularly busy day of work.First you go to the post office where Mrs Goggins will give you the letters or parcel to be delivered.You will also have to help herding Peter Fogg's sheep, and do all this against a time limit. The game includes a rendition of the show's music, as well as two difficultly levels - according to the inlay the easy version is for children, and the harder one for 'the serious gamer'.

A compilation of 4 quiz games

Centopeia is a shooter game where you are the operator of the earth's defense bases, with the mission of frustrating the attack of the terrible fleet of space centipedes that want to conquer our planet.

You have to cross a park from S to F. While doing this you encounter various mini games. During these mini games you can loose the game or be send back to the beginning.