My intention was that you weren't supposed to just bob and weave through the enemies but yea, little time to test led to way too fast enemies. About the coming out of nowhere, they can come from the bottom of the map where red auras are so you should always defend downwards. I did plan to have a little cut-scene or explanation of that in game but again, time was short due to the complexity of this idea.
Glad you liked the idea!