For practical invulnerability:
1. Raise your ice resistance above 100 and have the heal spell.
2. Find an ice knight and engage him. He will hit you for zero damage and restore your magic.
3. Hold down the heal spell button while the ice knight follows you around.
4. Have full health forever.
Simple, easy, and relaxing. I suggest adding a "turn off sound effects" option, because I'd like to hear just the music without the (very loud) "CHA-CHING" every time I collect something.
This game is very simple, but it works well. Crisp graphics and smooth movement are pluses, but once a black square spawned right where I was. That probably shouldn't happen. Quite difficult, but it's fair. This game is really just Tag with circles; the mechanics are exactly the same for both circles, so movement and avoidance are completely fair. I like what you've done with this concept. This isn't anything new, though. Try adding something unique. 3.6/5
The Outpost challenge is worded incorrectly. Instead of "Kill 2 enemies with all weapons", it should be "Kill 2 enemies with each weapon". To complete the challenge, you have to use each weapon to kill at least 2 enemies. I hope that clears it up for those who are confused.