imic is all about growth and getting tricky with creatures, and winning a game of Magic should always come as something of an afterthought. As a player with deep roots in casual multiplayer games, I can really identify with this sensibility, and I've worn a Simic pin on my jacket to Magic tournaments since it was given out at Grand Prix San Jose.
Here, I'm just going to play some little creatures and let them evolve, and maybe draw some cards, and eventually I expect to have enough gigantic creatures that I'll have won the game somehow.
This deck is mostly built to exploit Master Biomancer. My early creatures make mana and build up +1/+1 counters, which should allow me to hold off my opponent's creatures long enough that I can play Master Biomancer and start making huge creatures. Master Biomancer by itself makes all of my creatures pretty big, but not too ridiculous; however, if I play a second one, the first makes the second bigger, and then the two of them together make the rest of my creatures crazy. Alternatively, I can get even bigger even faster by using Bioshift to transfer counters from one of my cheap evolve creatures onto Master Biomancer. Prime Speaker Zegana will draw an absurd number of cards if Master Biomancer is in play, and Somberwald Sage and Gyre Sage will make sure that I can actually cast them all, at which point I'll find Craterhoof Behemoth pretty quickly to win no matter what my opponent's doing.