I like it! Given how high you need to raise a rock to squash a bug, there's a lot of skill in timing the drop right. My one critique is that there's a strict limit on how high of a score you can get: the number of bugs that can spawn in 30 seconds. For a game like this, it'd be nice to have a mechanic that (for example) extends the timer for each bug you squash. Of course, adding a mechanic is easier said than done in a 3-hour jam; I wouldn't be surprised if that suggestion was already on your to-do list.