Okay, so last time, I proposed something to do for those who dont like competing so much, and I have been thinking on this.
- The unlockables/collectibles are a very good idea.
- But, something better would be an achievement system, like on microsoft's live! Play hundred songs, you get an achievement. Complete Stealth on five songs, you get an achievement.
This could keep people playing for a long long time, trying to get the hardest achievements.
The achievement system could work perfectly with the profile screen for each player, so you could look what your friends have completed so far.