This is Towers, a prototype/demo made by a small team of developers, including some of the same folks behind Hawken. It looks a lot like Ico cosplaying as Monster Hunter.
Here’s a trailer, which the team say is 100% in-game and being controlled by human players (well, the people are being controlled, the monsters are all AI). The foliage-growing stuff looks cool:
It’s still very early days for the project — it doesn’t even have a publisher yet (remember, Hawken had a similar “come and sign us” reveal) — but there should be more coming out about it as the year goes on.