This was a fun game. It was pretty easy to get the hang of things once I saw it was auto firing. The upgrades themselves were nice, though the shop could use some work. It too quickly got to the point where rerolling cost more than the upgrades, and often I had multiple options for the same stat. My last reroll was going to cost 1024, and I only got enough just before winning. It would be nice if when you moved to the next wave the shop would reroll automatically once, or fill in the empty slots. Of course, on the other hand, sometimes there was a nice upgrade there early on that took me a few waves to buy, so it was nice to have that chance. Once I saw how the system worked I just bought every upgrade before rerolling.
If there were no upgrades in the shop, it would not focus on the reroll button, requiring use of the mouse. I primarily played with the controller. After clicking on the reroll button it did not update its value right away, but only did so after purchasing an upgrade.
The biggest complaint we have is the jittery screen shake when moving. I'm assuming it was a deliberate effect to reflect slimes jumping around, but it was a bit headache inducing. With that effect we'd not want to play this for too long at a time. It would be nice if there was a setting to reduce or remove the effect.
The Settings and Credits entries on the menu reacted to mouse hover, but did nothing when clicked on. Trying to use keyboard and controller did not work either.
Once I got a speed boost I was able to fly around the screen weaving through enemies and getting them to mostly clump together, making it easier to avoid them while circling. It felt like the collision shapes were very strongly in the player's favor and I rarely took damage, even when I thought I would. Once I got regen, I pretty much stayed right around full health.
The art is cute, and well done. The slimes are easy to distinguish, especially your player, which is really nice among such a jumble.