Wildings is the first mobile title from Metamoki, which is traditionally a social gaming company. Still, the game is pretty dynamic anyway. It reminds me a lot of Battleheart actually, which is an iOS game that I really love, though Wildings isn't quite as polished or complex.
The idea is that you control a set of creatures trying to defend a nest of baby birds, and you can guide your troops in real-time around the screen as you fend off attackers. You collect suns as you go (in a mechanic borrowed from Plants vs. Zombies, apparently), and then later on, those suns can be used to power your various abilities, doing things like slowing down attackers or even clearing them off the screen.
The action is fun and pretty well done, though the only real innovation is that you can tap faster on incoming enemies to take them down quicker. The game also has a relatively slow curve, too -- you have to collect boat pieces one by one to go off to other islands and get your troops upgraded, and the game isn't real clear on just how many pieces you need to move on.
Still, for the low, low price of free (which is what the game is on sale for right now), it's definitely worth a download. Wildings isn't exactly the most finished game around, but if you like the Battleheart-style of gameplay and want to try something new, check it out.