For the first semester coursework we were told to recreate a feature from an influential game. I figured there's no more influential game than Tetris (and indeed my accompanying report argued that point), so I decided to work on that. Of course, Tetris is a relatively simple game so I ended up recreating the entire thing rather than a single feature. My lecturer didn't mind. In the screenshot you can see what I ended up with. The game tracked the current play time in seconds, the number of lines cleared and the current level. Every 10 lines cleared meant a level-up, causing the tetrominoes to fall more quickly. A preview of the next shape is shown at the top. The currently falling shape can be rotated in either direction using A and B, moved left and right using the d-pad and caused to drop quickly by pressing down. All in all I was pretty happy with how it turned out.
You can download a rom of the game here. You'll need an emulator - I recommend Visual Boy Advance.