I'm looking for really simple mini-games, that I can add to my main game. The game needs to be fun (of course), simple, intuitive and fast (10 to 20 seconds, or 'turns' or so). With so many games out there, hopefully people can point me to a few. I've checked loads of games, but can't find any that I really like so far.
I tried a mini-game of my own creation, but it wasn't much fun. I made a simple 'Space Invaders', but that wasn't that much fun either (not when you need to play it over and over again) and took too long.
The game also needs to have some way of generating a score, though I imagine that most mini-games do that anyway.