This is a really cool idea, I like the decision making of the relics and the ways they effected the gameplay.
I took a while to realise that the time was my health and currency, my attention is never brought to the time when I get hit, or exit the shop since I'm focused on playing the game. Maybe some animation for losing time (timer shakes, goes red for a sec, makes a sound?) or even something as simple as putting "Cost: " before the health cost in the shop would have helped.
I did initially have a problem where I couldn't see the clickable button in the shop, and found that the case if I went fullscreen. I think there are some balancing issues, notably that nothing is an option. It could be interesting to force the player to take just one every other round. Mainly trying to avoid the player getting everything they want within the first few rounds (by limiting to 1) and stopping the player from not interacting with the system at all (by removing the option for nothing).
The actual gameplay did feel a slight bit bland, I'd love to see curses that are a bit more prominent, say forces the player to dash every x seconds, makes the projectiles do a boomerang motion stuff like that?
This is a really great jam game and I think it could be a very nice little game with some more polish.