I got a sudden desire to implement Tetris. I attempted to implement it in 4 hours, but then I discovered that rotating pieces in Tetris is more complicated than expected. In the end, it took around two days.
sample_game.mp4
Move the tetriminos with the arrow keys and rotate them using R and T.
This was built in my game engine, Varkor. In fact, it's the first real game that's been built using the engine. Hilariously, it doesn't use many of the features provided by the engine. It does, however, demonstrate a project that is completely decoupled from the engine's source.