I'm fine with the new control scheme...it makes things more challenging and reminds me of playing Super Metroid on my emulator (in which i used a keyboard exactly how I remapped the keys in this game, actually).
But GAWD I hate not being able to jump-shoot anymore. Dubya tee eff, mate? Needs a toggle, ASAP, lol.
That said, if you want to enable mouse support, you could make it so somehow using your moues to aim uses the same "resolution" of possible angles as the game currently allows. Ie, move your mouse in to the right and down, and your character aims 45 degrees down to the right, or something. idek.
Or just keep the control scheme, since it works, but encourage people to remap the default keybinds since they're TERRIBLE. XD
*edit*
I remapped it to WASD for movement as standard, Q and E I left for diagonals, and I use the num keypad for attacks. 123 are standard attacks, and I think 0 is special? Works for me just fine and lets me move with leftie like I'm used to for every game ever.