Hello! Thank you for playing our demo!
Sorry about the BG giving you motion sickness! As of right now, the demo handles it via a one time declaration when you first boot up the game, where it ask you if you want to play with motion transition. If you say nah, the major motions in game cease, and if you missed it the first time then my only troubleshoot suggestion is to remove and redownload the game. orz
In the extended demo we give you the chance to toggle the motion on and off in the settings, but otherwise, I'm sorry to say that the currently build doesn't have that yet. ^^,