A Roguelike Deckbuilder like Slay the Spire, but with a twist that instead of turn based, it is semi real time like Chrono Trigger.

A 2D procedural grid based dungeon generator with some light old school Roguelike gameplay. 

A 3D doom clone, supports 3D rendering and animations. Player can play in local multiplayer with PVP. And for the bonus mode, the player can instead play as a Demon, kill Marines and use their meat to recruit other Demons as ally.

A minecraft world generator with noise base biome generation. For bonus mode, blocks transmit heat and can evaporate or freeze based on heat. Water add humidity when evaporating, which will change position based on wind simulation and turn into rain when reaching certain threshold.