Dark Souls.
I like a challenge as much as the next guy but Dark Souls frustrated me to the point where it just wasn't how I wanted spend my spare time.
I would just play a game that you enjoy...not sure the kind of games you are into but an arcade shooter would be good.
You want to slowly build your muscle memory and if it was me, I would actually want to have fun while doing it to.
You could put it along the bottom of your monitor so you get some illumination against the desk.
Ultimately, you will be looking at it and using the setup so you can do whatever you like really.