Thanks for honest reviews and great suggestion!
1. I totally agree with too much text on tutorial but I don't have much time and I'n running out of idea at the moment but hey at least it's better than nothing! Definitely rework that if there's a chance for this game to get update.
2.There 2 types of enemies based on how they spawn the first type I called them, fixed position enemies cause they always near the task and the another type is spawn randomly near the player over time. I also come up with some formula to calculate enemies spawn interval based on how many variants in the map more variants less interval something like that to give the game a good balance.
also maybe spending too much time and over-engineer mechanic to balance the game is one of the reason why tutorial is suck, anyways thanks again for the review!