It's funny that Canabalt is barely a 4 on Kongregate but was a huge commercial success. Sometimes, these games that become big have a certain amount of irrational hype and crowd behavior attached to their success.
How to become really good at the game: Get plenty of healing and go in dungeons that are a breeze. Then guard and improve your defense skills. Now the next dungeon is slightly easier, and rinse and repeat.