WASD to navigate menus quickly, Q/E to navigate when you?ve unlocked quite a few store/inventory items. K to save and L and O at the same time to load. M to mute.
Note: You?ll have to zoom in the game at least twice for the resolution to be fixed, else the game will be too small! Also, make sure to open this in a new window or else the game will not run in the background. Both are not things I can fix fundamentally.
If you are confused on how to start off, here?s a small guide: