Well, I'm no expert, but I don't see the problem... It seems alright to me. Firstly, you only have 10 towers/pillars in a 50 card + deck. That's going to slow it down significantly. Secondly, you're vulnerable to creature control; have you played against a deck with antimatter? If you get this deck set up, it's very powerful; lots of healing and damage dealing, as well as control. However, it's balanced because it seems to be really slow and there are plenty of counters (Gravity shield, antimatter, earthquakes or devourers), if you face certain decks.