Osu! looks pretty intense and fun. I wonder how well it works on a touchscreen device like a Surface.

It'd certainly play very well if it works well. Looks like it's based directly on the Ouendan series (Elite Beat Agents) for the Nintendo DS where the games are played with a stylus.

I didn't know about osu! but I love Elite Beat Agents so I will definitely be checking this out!

Most of the hardcore Osu players play with wacom or equivalent tablets. Absolute positioning is a huge advantage.