[isukun]

I like the tag team rules. They're simple and don't require too many tweaks to the main game. The only sticking point for me is wouldn't having two people at level ten taking on the final boss make it easier in most cases? Maybe it would be good to tack on a higher level for the boss, like maybe 30 instead of 20? Just to make it a little easier for other teams to make that fight harder for the leading team.

Edit: Another problem you might run into with the team rules is that by having established teams, you effectively eliminate most reasons to interact positively with players outside your team. You're pretty much limiting people to only helping their teammates to get both players to ten fastest. It makes it into a more straight competitive game where you're not really backstabbing people because you need a particular player to succeed in order to win.

Another alternative which encourages more team based play, but doesn't create specific teams might be to add a winning condition that requires two people to finish the game together and ups the level of the end boss. Maybe have the boss level be variable based on the number of players at level 10. Like 40 for 2 and add 20 for each additional player at level 10 in the game. This both encourages players to help each other out to get multiple people in range of winning, but also keeps some backstabbing elements alive since you don't want a lot of people meeting the victory conditions.