@lioness you attack automatically and the only input you have in the moment-to-moment gameplay is moving around and selecting which powerup you get when you level up, which sounds boring but winds up being quite satisfying, because you get strong enough over the course of a run that you wind up mowing down huge hordes of the smaller enemies
also runs have a time limit, usually 30 minutes, which makes it easy to play for short periods. you CAN circumvent the limit but not til much later