This game is just lovely. It's really simple, but extremely engaging and fun. It slowly turns into a sort of bullet hell, and I love how fast paced it is. The exchange mechanic is probably one of my favorites so far.
Not getting just get an upgrade, but a random weapon, makes it so you want to try and dodge as much as possible when you get a good weapon because you don't want to switch. Overall, I liked it a lot, great job!