Neat game, but it is really hard to enjoy with these controls. For most people it is not a problem, but the Z and the Y button are flipped on some keyboards (Hungarian, German etc) so I would recommend either not using a control scheme like this, or providing alternatives (like: ASD does the same thing), or adding the ability to rebind. Also, using the up button, or space for jumping would feel more natural, so I think it's worth considering to rebind the controls.
The actual game was fun, but fighting even a simple spider was tedious (because controls). The game had a quite a lot of enemy variety, and a shop with unique upgrades, so great job! :)