Land Fall Deck

First off, great start. There are a few tweaks I'd make, but if you're keeping this Standard legal that makes it harder.

I'd lose the Blighted Woodlands in favor of two more Evolving Wilds. A free double land drop is going to be more useful and versatile, and and dropping one mid-combat with Swell of Growth is just awesome. I'd also drop Slab Hammer and replace it with Sword of the Animist. Again, you'll get a lot more mileage from the latter. The other thing to keep in mind is that this deck archetype will generally be better playing the early to mid-game. With enough cheap mana ramp, triggering Landfall multiple times a turn, you're able to swing in pretty hard early on. But if you wait too long, you'll run out of steam and your opponent is going to catch up. So I'd lose expensive cards like Scour from Existence and Roiling Thunder in favor of cheap bun like Flame Slash. I know it seems like all the ramp should let you play more expensive cards, which it can, but by the time you've dropped that many lands, you want to be using your resources to demolish your opponent by playing cards like Omnath or Animist's Awakening, not pick off a few of his creatures. Taking out his creatures early on with Flame Slash will also set you up to dominate the board right off the bat. I'd drop the Retreat enchantments for a few more creatures. Snapping Gnarlid is a solid choice.

Just my two cents, feel free to take it or leave it.