Okay I have some feedback.
Here's what I like:
- it's all very "juicy" and alive: lots of particles, screen shake, everything is animated (tweened).
- in principle, there's a clear tutorial that takes you through everything.
- the game play is fast.
Here's what I don't like:
- The downside of all that juice is that it's visually very "noisy": it's hard to understand what's going on.
- There's no time to learn what everything is or does: if you take it slow and look at the pickups or enemy behaviors, you're dead. The first wave is immediately all out. That's good for experienced players (with full skill trees), but probably there should be a slow training mode where enemies and abilities are introduced one by one. Possibly without gaining XP.
- For such a fast and short game, replaying is frustratingly slow: it's possible that you die after 2 seconds, but then you need to wait more than 5 seconds for the UI animation, to go back to the menu, and to restart (at least that's what it feels like - I didn't time it). There needs to be an immediate restart button - I don't care about my newly gained XP, unless I got very far.
- Some of the tutorial text is absolutely tiny! (When viewed on an average laptop screen.) The smallest fonts need to be at least twice as big, if not more.