I often sacrifice brute force or overall effectiveness in my decks for combos that feed into themselves and generate the conditions needed to cause them again. Experimental Growth definitely fits the bill on this one - the main combo comes from card draw and spells creating counters, which are then removed for card draw, and then hopefully, more spells, which continues the combo.
Zameck Guildmage and Sage of Fables remove counters for card draw (the sage also combos well with the high number of Wizards in the deck). Protean Hydra directly benefits from this, while Forgotten Ancients and Lorescale Coatl replenish themselves easily from the removed counters, both averaging a net neutral from one or two uses a turn. Fathom Mage is really my preferred target, though, as reducing the counter numbers on it allows it to evolve again for more card draw.
The Ancient is a nice after-its-in-play +1/+1 counter mover that is guaranteed a counter for each creature the opponent has, and Simic Manipulator allows me to have some creature control to make up for my lack of fliers/tramplers.
Kalonian Hydra was just too fitting to not be in this deck.
The biggest issues I'm having right now are with the mana curve - so many things on the 3-drop, and a lot of the things I would play after that have extra costs in following turns.
Thoughts? Criticisms? Suggestions? +1 if it seems fun.