1D: (Single-dimensional gameplay) The game takes place along only a single dimension.

Collaborative Casual/Hardcore: (Two players: one casual, one hardcore) Collaborative play for two, but one player has more to do than the other (or the difficulty level is different between them).

Good Vibrations: (Game contains haptic feedback) Make a game where haptic feedback (e.g. rumble or force-feedback) is a key ingredient.