Sonic: Before the Sequel

Sonic Before the Sequel (abbreviated Sonic BTS) is a fan game created by LakeFeperd that is meant to explain the events that may have taken place between Sonic the Hedgehog 1 and Sonic the Hedgehog 2. In it, the player plays as Sonic and Tails, alternating between the duo through numerous zones as Sonic goes to stop Dr. Eggman from launching the Death Egg, with Tails trying to keep up and eventually meet and team up with Sonic. An update was released during SAGE 2012, adding improved graphics, an original soundtrack made by Falk, KgZ, Andy Tunstall & Funk Fiction, and a bonus boss if you reach the good ending. A sequel, Sonic After the Sequel, and an interequel, Sonic Before the Sequel Aftermath (which has now formed into another fangame by LakeFeperd called Sonic Chrono Adventure), were released as well.

Sonic: After the Sequel (abbreviated Sonic ATS), is a fan game created by LakeFeperd that is meant to explain the events that may have taken place between Sonic the Hedgehog 2 and Sonic 3 and Knuckles. In it, the player plays as Sonic and Tails, racing through numerous zones as Sonic and Tails go out to stop Dr. Eggman from crashing the Death Egg into (and attacking), the new, mysterious island known as Angel Island. It is the sequel to Sonic Before the Sequel.

Sonic Robo Blast 2, abbreviated as SRB2, is a fan game for Windows and DOS platforms. It is a 3D platformer developed by a group called Sonic Team Junior, using a modified version of the Doom Legacy source port of Doom, to allow for such things as optional analog control and true room-over-room (something not possible in the standard Doom engine), as well as the standard gameplay elements Sonic games are known for. It has been in the works since 1998 and is currently nearing completion, though several parts of the game are still missing. Sonic Robo Blast 2 is closely inspired by the original 2D Sonic games for the Genesis and attempts to recreate a game with this style in 3D, though it also borrows elements from the current Sonic games, such as Sonic's signature Air Spin Attack. Entirely original to SRB2 is its Multiplayer mode, a variation of classic first-person shooter games with Sonic elements. Due to being built with a modified Doom Legacy engine, the game is also very easily customizable. Custom levels, characters and even source code modifications can be created with the help of external editors.

Sonic Chrono Adventure is the last in LakeFeperd's series of Sonic fangames made in Sonic Worlds, an engine built within Multimedia Fusion 2. It was developed at a time After The Sequel was feature-complete but also waiting for the sound team to finish composing their original soundtrack. Not wanting to exploit them, Lake went with existing songs for this final installment and released it in December 2013.

Help Fireboy and Watergirl explore the 7 Elemental temples! Solve the puzzles, beat the times, and collect all the diamonds! Play alone or with a friend to join Fireboy and Watergirl in this new adventure!

Sonic: Before the Sequel - Aftermath is a short fangame combining traditional Classic Sonic gameplay with the exploration found in the Metroidvania genre. This game is often considered to be the spiritual prequel to Sonic Chrono Adventure.

A truly expansive Mario fangame based on Super Mario 64 that combines elements between it, Super Mario Sunshine, and Super Mario Galaxy. Released in 2009 and featuring 64 Shine Sprites and another 64 Star Coins to collect, it remains the largest-scale Flash-based Mario fangame to this day.

In Sonic.EXE, you start as Tails and move through a level. But things don't look right. All the little animals have been slaughtered. Then you find Sonic. But Sonic doesn't look right, either. He tells you he wants to play but losing this game can be fatal. After Tails, you play as Knuckles the Echidna then as Dr. Robotnic. Sonic gets no nicer, however.

Sonic Encore is a fan game that re-imagines some of the classic levels from the Sonic 2D era into a more modern 3D environmental setting.

Nights: Moonlight Dreams... is a fan game of Nights into Dreams, developed by Marco Medina.

Sonic Dimensions is a 2D fangame created by Phantom-Radea that takes inspiration from the gameplay style of Sonic Rush.