arrow keys to move survive as long as you can you need to not touch(collide with) other stuff but when you get really close to enemy your energy(the lower rightwards bar) will increase. (yep, just like deltarune) energy is just like your hp. when you got hit, your energy will decrease. when you got hit when your energy is 0, you ded.
thanks @noob-lolxd for almost everything also thanks pvz and deltarune ALL LEVELS ARE POSSIBLE