I like the animations and overall style of the game, the attacks have a nice impact too, though the camera shake started getting a bit nauseating after a while. Not sure if tying jump height to level ups was also entirely necessary, as it had to be upgraded quite a lot on top of getting the double jump in order to reach a platform. Or was this on purpose, to have it be a build path sacrificing attack etc. for increased mobility?
Anyway the options menu was quite impressive, though maybe including only the necessary input options on the list would do. Personally I like to turn "ui_up" etc. direction inputs into the movement actions.
At least on my browser on HTML version the amount of enemies that got spawned made the game quite laggy, especially the zombies that got stacked under me while I was standing on a platform.
In the end I beat the story mode, had fun!