The enemies get faster as the game goes on. I just wanted them to start off as basically static until the player gets used to moving slowly. Despite the movement speed, it's more designed for you to go a little slower by tapping the button instead of holding forward. Don't worry, I'll definitely put a dedicated run button in the next game. The levels will have more things do to than collect an arbitrary amount of objects. There will be more enemies and characters, too. I just wanted to focus more on hazards than enemies when the combat was so clunky and the control was a little too loose, but I might have left the levels a little barren.
I made this game mostly for experience and to lay the groundwork for future ideas, but it was never intended to be a serious attempt at making a deep complex game. There are a few bosses in this game, but there will be more frequent in future games. In fact, my other game I was working on does have a good amount of bosses in the later half.