Hey I gave your game a play. It was fun. The core bullet heaven is executed well, with a lot to like, but there are also some shortcomings. Here's some notes on specific things:
--Base gameplay, destroying ships, is super satisfying. Mouse aim is a little clunky, but also makes it easy to quickly reverse where you're firing, which helps a lot. Not sure if there's any way to tweak it, or if it even needs fixing, but wanted to note it.
--I like the weapons you have, but they are all just variations on the same thing I guess? Just projectiles with different behaviors. You could have a shield (like the garlic in VS), or drones that will target the enemies.
--I will say I liked the variations of the weapons upgrades and seeing how they affected the projectiles. It was fun having different builds that had different weapons get really powerful. The wall of bombs is the best!\
--For the weapon upgrades, it was a little confusing at first, when upgrading a weapon to another level, I at first thought all of the cards were the same, and I didn't really want to read all of the text on it. Maybe coming up with a way to visually communicate the different types of upgrades would be good.
--Enemy looks and behavior could use some variety I think. Though the base variation between stronger and weaker enemies is good, it would be nice to have other things to mix it up. I'm trying to remember examples from VS, but I can't. Maybe like the big swarm of bats coming at you, and the ring of plants.
--I like the loop of coming back around and buying upgrades after each run, and that the runs are pretty short. The meta upgrades could use some better communication about what they do.
Anyway that's what I've got. It's definitely a game I could see myself sinking a few hours into if there were a lot of upgrades and maybe some different scenarios/levels to try out. Nice work!