This is a cool little game, and I played it through to the end screen. You've accomplished a lot for a five day jam in terms of the levels and upgrades.
A few bits of feedback from my playthru:
- I didn't bother fighting any enemies after the tutorial. Especially in level 2, where time was really tight, it felt more effective to just let them chase me
- I kind of regretted fully upgrading the speed stat, as it made the game hard to control
- Other comments also mentioned this, but it might be less awkward to control if the attack button was mapped to something easy to press with your other hand while using WASD to move
Still, I really like this one!