RunGunJumpGun is one of the best autorunners since Canabalt
How many things can you remember at once? I know the answer when it comes to me! It's two. I can remember two things at the same time, and I can just about switch between them if I absolutely have to.
This is bad news for me, because the actual number of things you're meant to be able to remember is something like seven (+/-two). I say it's something like that, because I've forgotten. That said, it's also good news for me, because it means I can just about play RunGunJumpGun, a 2D autorunner game in which you have two controls: you can shoot your gun downwards to give you some lift, and you can shoot it forwards to blow up things that are ahead of you.
Ulp! And it's bad news for me again, because to play RunGunJumpGun well, you really need to be able to remember three things. It's not enough to simply survive - to eke out a kind of life by leaping over spikes, but not so high that you leap up into different spikes, and by blasting away at barrels that would otherwise leave you squished on geometry. To really thrive in RunGunJumpGun, you need to collect the little doodads scattered around each level, often in hard-to-reach places. (I have, of course, forgotten what these doodads are called.)