I had this error on desktop linux too (didn't test on my Steam Deck) and it seems to be related to the path of the game executable. If you have any colon (:) in the pathname, remove/change them, the game will launch. So... some shenanigan with pathname quoting or escaping? Otherwise the game runs great, 100%ed it.
Edit: colon is used as a separator for paths to search for files (in our case, libraries) in some environment variables. So here's my error. Yours is very similar but not 100% sure it's identical.