No crashes, and my PC is good enough that I couldn't notice perf issues. Very early on so idk what to say other than you're mostly cloning the basics of RoR2. I did notice that mana regens and enemy projectiles still move while paused.
I suppose one oddity is that the first boss type monster kept appearing and disappearing, can't tell if he was cloaking or if the model was bugging. I think it's intentional since I couldn't target him during that? But half of the combat was waiting for him to uncloak.
Keep up the good work.