This game is really fun but only as the fire class. The other two classes are pretty horrible in my opinion by comparison. The lightning class may have a nice chain ability but it doesnt mean anything if there is only 1 enemy left. The poison class's arrow increaser decreases the main arrows damage to 50% as well so if you invest 9 points into it for 3 arrows you are only really getting 150% damage instead of 200%. As for the fire class it's class skills are off the charts compared to the other two. Aside from the head shot challenge there isnt anything with this class that I have remotely had a problem with which makes it a very over powered class compared to the other two (if you were going for balancing them for play styles and not using them as difficulty lvls).
In any case I really do enjoy this game, but I wish that the other two classes were a bit better.