i think the game in general lacks a lot of "themepark" flatrides. the ones we have now are more funfair flatrides, and dont get me wrong they are good.
but in terms of flatrides that you encounter in those heavily decorated theme parks there is nothing there. flying theatre, simulator (like a barebones box that we can theme ourself and add a screen etc), madhouse, moving platform ride system. also in terms of freefall towers it would be amazing to have ones that we simply can attach to walls like mystery castle in phantasialand. theres so much potential there with beeing able to add scenery to rides, i realy hope frontier realises this