I remember that the dev of Legend of Grimrock added an option for movement with the mouse because a disabled gamer wanted to play. Maybe that second friend should check that and the 2nd game out.

Using a mouse with your non dominant hand is annoying…

Yeah, for PC they’ll probably have to grit their teeth and power through the discomfort. An alternative is getting a hand in some old emulated games. Anything from the NES era can be mapped to 4 movements + 4 buttons (start, select, A, B), which on a keyboard could be WASD + Q, E, R and F. Dunno how to set something similar on a Deck.