Quest for Galaxia has TERRIBLE slow down on 60Hz STe and Mega STe machines. The game runs fine if the computer is set to 50Hz before launching. Thought I would mention it here incase you wanted to update the launcher. I thought the game was just crap in that respect until I had the idea to set 50Hz before launch. At 50Hz it is very fast / smooth.
Yes, and that's not only such case. The reason is that game's code is very related with vertical sync (Vblank). It must perform all tasks in time between 2 Vblanks - and it is shorter when vfreq is 60 Hz. Then may happen that additional vblank wait happens, and that makes slowdown.