The very first thing I did was run into the lava. Oops.
Count me among those who liked the giant band. The dancing vocalist monster dominated my attention for the first few times I played, and got me shoved into the lava another handful of times.
The big boys that spawn on 5 and 10 are honestly less menacing than the little basic zombies, though, which feels a bit backward from what I assume was intended. If I had to pick something to grouse about, it would be the size of the reticle in the center of the screen. If it were smaller, or had a bit of transparency, it would be much easier to pick off distant targets.