Over my 68 hours of play, here's what I noticed:

• Bug: With screenshake on, holding left mouse button on a chest to buy it can accidentally spend money on nearby chests
• Issue: Clouds and smoke should be rendered on a layer behind gameplay elements like enemies and bullets. Needless visibility issue.
• Issue: In late game endless mode, it can be impossible to select the correct chests and items or avoid picking up stuff you don't want due to everything being so close together. This can be fixed by removing chests, opened or not, that have been left alone for a certain number of waves. Then you can use the freed up screen area to space everything out.
• Issue: In late game, the pause menu item view gets clogged up due to lack of space and you can't accurately click on what you want to see. A fix would be making the item section bigger, mostly by expanding it into the Active Item section because that's an entire third of the items/weapons UI window but only ever has one item in it. It's a waste of space. Also, make item icons dynamically smaller (to a point) as there are more of them, plus allow arrow keys to scroll through items one by one. I don't remember if the arrow key thing is already in the game, but I'm typing it here just in case it isn't. A bonus would be adding an option to sort items by how recently they were picked up.
• QoL: Add a function to discard weapons. If you pick up a weapon you don't like, and/or find a better-in-every-way weapon after the fact, it does nothing but clog up the scroll bar since you won't be using it anyway. Contrary to item discarding, which may be OP, most weapons have no effects when you're not actively using them. If it is still a balance issue, make stats like jet weight for heavy weapons not go away after discarding.
• QoL: Add a button to view jet stats when in pause menu, even if you're not in hyperspace shop intermissions.