The timed challenge medals are all based on times not utilizing any abilities.Regarding the freezing thing, I've never encountered it myself, so I'm guessing it's machine dependant.Thanks for playing!
Doing ability-less runs could propose a nice challenge for better players, I guess I really do suck at this game then lol.
Sidenote : I also noticed that the random freezing totally disappeared when I started playing at a different resolution than fullscreen.
