The following features required to run Godot projects on the Web are missing:
Cross Origin Isolation - Check web server configuration (send correct headers)
SharedArrayBuffer - Check web server configuration (send correct headers)

pretty fun idea! this would be very worth expanding upon

...Your core idea isn't bad

There's a lot of lag spikes early on. Stops eventually, but I was worried about my browser crashing after getting the thorn minion

Cost scaling is way too aggressive. Gets hard to buy stuff pretty quickly, and the difference in values between rarities isn't reflected in the prices after buying a few commons

Enemies could use more differences in behaviour

The shop being on a timer feels pointless? Just let the player open it whenever, and force the payment for a restock

Game won't load at all. Tried like 10 times.

I experienced frequent lag spikes and crashes.

It seems I already came with "arcane spell" at level 2 by default, but what attack is this? The regular shot? Then isn't this upgrade the same as "Mirror"? Shouldn't arcane spell lvl 2 say how much it's increasing reload by?

Buying a reroll doesn't affect how my balance appears on the shop screen.

I don't know what it means to increase an attack's "durability".