Simple and to the point, which is perfect for a minigame! :) I ended up with 17 points (not sure if that's good or not), but at least I didn't get hit by a boulder.
If you're planning on working on this more, one suggestion I'd like to make is to move the spawning events a tile or two higher, so they're off the screen. Right now they sometimes flash and change as they're setting, which is a bit distracting. It's nothing major, just something I wanted to mention. :)