I even have an idea or two to share.
Maze Race:
Wizards go at each other in a battle of speed and agility, blasting through all of the hazards and monsters that await them in the depths.
No magicks (Sorry, no hasting through this one)
A small map that would be two simple lines, how far you are in the maze next to a line that shows how far in the maze your friend(s) are into the maze.
Randomly Generated Mazes to make it stay fresh(er) then simply generating maps.
Hot Goblin:
Use your power of air to blow a goblin around towards your friends, passing the suicide bomb back and fourth, no spells or off-hand weapons/staff use effects.
Keep passing the goblin around until he eventually explodes, he'll blow up on the last person who successfully hit the goblin with air.
Freeze Tag - to the eXTREME!(Idea is Work in Progress as far as guidelines go):
Simply a run around game, whoever is it would have to be capable of freezing their opponents, those who aren't it would have to run away from whoever is "it" in order stay in the game, other non-it players would be allowed to remove freeze from players who were unfortunate enough to be frozen. While frozen, you would not be allowed to simply cast fire on yourself to remove or place fire immunity upon yourself. Whoever is it will not be allowed to use rock + water/frost to make tagging easier, but they will be allowed to use beam combinations in order to make it more fair, just as non-it players may be allowed to use Haste to make it more balanced.
Note: Freeze would stay on the entire match until removed or until game is over.
Tower Defense:
Use your power of magic and your mind as you make use of your elemental minions as guard towers to fight the oncoming horde!
That's all I have for now, I will have to come up with more ideas as they come.