Here is a basic guide to getting Roller coaster tycoon world (Mostly) working on the Steam Deck with some issues



Enable Proton 6.3.8 For the best performance
Limit FPS to 30
Lower all graphics settings for the game to low and turn on vsync

(Optional but recommended) On Steam Deck, Lower the resolution for the game and turn on the Steam Deck FSR for the game to improve performance further.

Use the launch commands of:
PROTON_USE_FSYNC=1 PROTON_USE_DXVK=1 %command% -force-d3d9


Credit to the article linked below and its author for the idea of using -force-d3d9
https://steamproxy.net/app/282560/discussions/0/365163686041956404/


For best battery life limit the fps to 25 instead of the previously mentioned 30

Disclaimer:
External website mods can assist in improving the performance of the game on Steam Deck further. However, they will not be linked here.

Performance isn't the best, there is still stutters at the current way i have set it up with no mods, i am unsure if the performance is down to the game itself or proton building a shader cache for the game, due to a potential lack of players of the game on Steam Deck and/or Linux as a whole.