Well, some challenges requires some fast precision movement skills. The game is very friendly about checkpoints though and it's non-linear (especially chapter 3) so you can skip many areas. Check out the game demo on the website, if you can complete that, you can definitely play the full version.
I can unfortunately not guarantee it won't require reflexes that are too quick for you. However, I have an idea; sooner or later I need to update the game (I'm sure that we will find some small issues to fix), and I could add in a slow-motion button that can be enabled through the game options. Keep an eye on the forum, I'll announce this if I add it.
Knowing you, hmpf, your completionist attitude will destroy you on some of the harder challenges.. :P (and there are some very, very hard challenges.)
Well, I've started chapter 2 now, and... I give up. The ball is too fast for me. I just can't react quickly enough. (Also, I seem to have a poor grasp on bouncy ball physics, lol. I didn't even get out of the very first cave after the Nicklas sprite left me to my own devices.) :-(Try Advanced control scheme. When keys are for both hands it may get easier. I have A for Dampen *and* Transform, S for Jump and D for power use.
A slow-motion mode is on my to-do list. After Christmas, I'll start working on some minor fixes and will add that while I'm at it.More achievement dances!