Thanks for the review!
Yes the freezing/crashing issue seems to be a common one. I personally could not reproduce that consistently in my local environment, but I would try some measures like preloading assets instead of loading them on the fly for better performance.
A slay the spire-like was not part of my vision. The end goal (if the game ends up being "completed") was to add multiplayer. I would need at least four fighters available for that to happen, so each player would get two random fighters to pick from in the beginning. I do plan to have a "story mode" and make a story line for each fighter to characterize them a bit more.
Staggering is pretty powerful. I added the staggering cap of 5 to nerf it. Maybe it could be lowered more or the resistances could be higher. But most moves that are good at staggering require high stamina or a long time to finish, so you're not likely going to lose from just being hit by a single staggering spree (two or more would definitely do it though). I'm also planning to add a draw pile and discard pile view for both the opponent and the player (only draw pile count for the opponent), so it will become more predicable what cards the opponent would have ready in their hand (if you're familiar with their deck, which is ultimately how the player's expected to get better at this game).