This is a Green Ramp up and Beat down deck. It uses all X cost creatures so that you can get them down at any point in the game, however it doesn't have a lot of them so you need to use Sylvan Library and possibly Enshrined Memories (Not sure if this one should stay).
It's a bit enchantment heavy but they are well used.

On my first play through of the first cut of this deck, I had an exceptionally good draw and had a 10/10 Protean Hydra down on turn 5.

This deck was originally built around the Hall of Gemstone to shut down multicoloured decks.