Here a few options from my portfolio:
Tiny Dungeon, a 3D RPG action third person game with enemies to defeat and coins to collect! (About 5-10 minutes).
Final Boss Fight, a retro, local-multiplayer platforming game where one of you is the final boss in the other's game! (About 5 minutes)
The Tower Master's Treasure Hoard, a strategy deckbuilding roguelike card game, where you balance offense and defense to steal the Tower Master's biscuit hoard! (About 10-20 minutes) (Currently in a demo state, but if you come back in a bit more than a week, it will receive a major update and be much more engaging).
(EDIT: Tower Master's Treasure Hoard has been updated and is now a great game)
It would be amazing if you could check out one of them!