I have tried getting the game to launch through adding gog galaxy and heroic but I always end up with an error saying misingini. If anyone can help you would be a godsend, thank you.

hi!
I am also interested in this. I hope to make it work on the steam deck

Hello!
I have managed to get it working on the steam deck. In desktop mode installing GOG through Lutris. Lutris can be installed through discovery in the desktop mode of the steam deck.
Once the gog is installed there, fiddling around with the video settings a bit and it works.
and Lutris lets you add it to steam game mode.
I hope it's worth it to you

I was thinking of buying a Steam Deck mainly to play this game on it because I get motion sick playing on my PC. Are you able to use the excellent mods with it?

I'm not sure. I have installed other games with mods without problems, but they were for native Steam games. Think that Steam Deck is based on Linux and the game to make it work has to emulate Windows (explained poorly). Since it does not work natively, it will surely cause problems.
Right now I'm trying to install a mod in Undiying that fixes textures and adds subtitles and it gives me an error that blocks the steamd deck...
Maybe buying it just for one game is not a very good idea, especially given how much it costs to make this one work in particular...