I feel this is the perfect example of a good idea being held back by rough execution.
The choice between taking on another, more difficult fight in return for a better upgrade is a good take on risk vs. reward. It's also a refreshing take on the theme and fits nicely with the roguelike genre.
However, there is no indicator for where enemies spawn, nor does it seem to be affected by the player's position. As such, it is possible for them to spawn right next to you. One of my attempts ended suddenly when I ran into a newly spawned enemy and died before I could even react. There is also a weirdness with when a round ends; sometimes the fight would be considered "won" despite an enemy still standing. Since you attack by clicking, this can further lead to accidently clicking "Loop" and taking on a fight you're not equipped to handle.
There are other things that could be improved upon as well, e.g. adding music and sfx, balancing, a main menu, etc., but those clearly had to be cut due to time constraints.
I genuinely want to enjoy this game and if you update in the future, I will gladly check it out again, but I feel I cannot enjoy it as things stand.