Hey Boqui, thanks for the honest feedback!
If you're still interested in giving the grapple a try, if you download the first file 'Movement Playground' that's a stripped down, greybox room with just the movement upgrades and a place to try them. I havent seen the movement playground crash, it seems like just the normal map. I'd love your opinion on how the grapple and swing feel and any other suggestions you might have for making a more satisfying controller!