Thank you for playing and I really appreciate your detailed feedback!
Couple of comments:
Shop is definitely buggy. I put together all the items last minute and had no time balancing the cost to value, or to have a system which pulls lower cost items earlier in the game. I 100% intended that the shop reroll itself for free when you go to the next wave, or if it runs out of items and not punish player for buying more, but totally forgot about this last minute. The shop can be improved a lot, thanks for your feedback on it!
The jittery screen shake is not intended, and I didn't notice it on my end. I'm not sure if this is hardware specific on your browser, or a visual bug. Does this happen right from the start, or when there are tons of enemies on the screen in later waves?
Settings button on title screen is a dummy. I wanted to add basic audio adjustments, but couldn't get to it. Credits button should work, not sure if I broke something last minute haha
You're right. With speed upgrades, it's super easy to avoid enemies and they do tend to "ball up" once you do a few circles around them. I plan on adding different enemy movement types in addition to a plain "follow" currently. Also want to add ranged enemies, which will mix things up and be a better challenge.
Thanks for the art appreciation, I'm a beginner at drawing pixel art, but I was very happy with what I could make.
Appreciate your feedback. I'll check out your game soon!