Sonny is my favorite Flash game, and Sonny 2 is going to come out in the next week or two! Definitely check it out if you feel like a short, fun RPG about zombies.
http://armorgames.com/play/505/sonny
Some class tips: Guardian is the easiest class for beginners, but Assassin is the best class for the bosses in the final zone. I feel that they're the two best classes in the game. Gunslingers turn out pretty good but they're the hardest class to use in the first three zones. Destroyers are okay, but they're a bit one-dimensional and their lack of speed really hurts them in the final zone.