Oh, a game with "retro" and "pixel art" graphics that doesn't look cheap but actually appealing, a quite rare sight. Not exactly my genre though so to the wishlist it goes for now.

Groovy! Congratulations, it's finally here!
Thank you, GOG!

All options and settings for Souldiers:
https://www.youtube.com/watch?v=XkgTAj2agSs
Thankfully you can disable screen shake.

No mouse support. 2 handed keyboard game or controller game.
Pass.

How would that work ?, it's a platform game...

I'm on a really strict budget now, but I'll try to get this when I can. If your mouse has buttons on the side, you can assign keyboard inputs to the side buttons.

Sounds like every other platformer. Talk about unreasonable expectations. *rolls eyes*

WASD/Space (or your preferred equivalent) for the platforming/jumping, active/passive abilities (like slashing/shooting, dashing, etc) on LMB/RMB, secondary things like throwing grenades or alternate weapon modes on the middle mouse button/button(s) on the side of the mouse.

I get the keyboard requirements, I've used them on occasions in platform games when no controller has been available. But the mouse requirements still have me stumped, and seem a little convoluted, but, 'to each, their own', I guess...

beautiful, it makes me think of a horizontal scrolling Loop Hero visually

Not that it matters however "Platformer" suites it better than "Action".

There are a lot of things I can overlook, but this just sounds like griping for the sake of griping. You may as well be mad at GOG because the game doesn't work with your typewriter.

Cringey compound word title aside, that is some solid pixel art, wishlisting this one.