Hello. Could you please confirm whether Castle of Illusion's fps lock is actually 67 fps and not 60 fps? I'm reffering to this edit you did. It seems to be locked to 60 fps in my experience and I haven't seen a mention of 67 fps in Steam Community.
Topic on User talk:Keith
When the game's frame limiter is enabled, the game runs capped at 67 FPS on my 120 Hz display.
You could try forcing vsync off to see if it goes above 60 FPS, because the game has it enabled by default.
It seems you are right. I didn't consider testing with v-sync off and frame limiter for some reason. I undid my edit then, thanks for the answer.