I've been trying to play osu! with RED/CYAN 3D glasses and it has given me interesting effect like beatmap skins. Sadly IZ3D software doesn't work on osu! so it is impossible to get that effect. Is it possible to make Anaglyphic software for osu?
maybe you should go to feature requests and make this a request. also can't you just skin hitcircles and others to have a 3D effect? EDIT: you can skin it like this http://puu.sh/pR1Zi/dd6a7c8be6.osk