Not a bad start. As you mentioned, as it is, the game tends to get a bit repetitive pretty quickly and it seems pretty easy to cheese by just spamming rmb. I would suggest two things right now:
- add some variety to enemy patterns
- add an attack cooldown or shorten the time during which an attack can actually hurt the enemy.
Once you’ve made the combat system feel a little better, I think you can start designing some neat levels with this. Keep it up!