Well the initial idea is really good, but implementation could be better, except the inexistence of gamefeel, there are some balancing issues, enemies are too fast, and I guess they put player into invulnerability state when damaged, altho this is not enough on too many levels, since enemies are melee oriented you had to add a little bit kickback when player gets damage, this fixes player being damaged too many times repetitively without a chance to avoid, and adds a little bit gamefeel.