I think there are a few things that make players a bit frustrating.
It requires a double jump to stand on the top tiles and the character is running a bit too fast. This makes it hard to control the character to an expected position.
Also, when fighting against enemies on the top, one not only has to press asdw(and takes care of double jump) but also has to use the mouse.
The overall mechanism is good, but just a bit too hard for the opening play.