I would really like to see a "pvp" mod next to the co-op mod for osu!mania, which doesn't split up the beatmap into 2, but duplicates it so 2 players can pvp on a single computer. Unranked ofc (just like co-op), and the score at the end/for online is the average of both scores. (would be even cooler if the second player could login additionally but I am pretty sure this will never happen).