I picked this up after seeing it got approved in the recent Steam Greenlight. The premise of the game is fairly simple: you've been infected with a plague and have to explore an abandoned island to synthesize a cure while keeping the fever and delerium at bay. The game is built on three fairly straightforward mechanics: harvesting plants, researching them and making things from them; mapping the island using a compass and triangulation of landmarks; and using stealth (and occasionally running like hell) to avoid a creature that's stalking you.
The game is remarkably pretty considering it was developed by a two-man team, and has an amazing sense of place. The gameplay itself is quite unusual - the closest analogy I can think of is wandering around the countryside in something like Crysis but without knowing where you are on the map (unless you can find a couple of landmarks). It's really quite reminiscent of what I remember of orienteering in school camp when I was a kid. It's very immersive since there's minimal UI: you judge your exhaustion by the sound of your breath, your health/fever by the distortion of the screen, and your notes and map are recorded in a journal. About all you get is an icon in the middle of the screen when you can interact with something. The controls take a bit of getting used to since your character has momentum and some parts of the mapping etc. could have used a little more polish, but they're fairly minor quibbles. The creature is very well done: you can go for an hour or two without seeing it, but once it gets your trail it can be hard to lose... and it's a sneaky bugger. Especially at night.
It's an odd game: sort of an extreme version of Skyrim's plant harvesting and alchemy with just a dash of Amnesia thrown in. Currently $13.50 on Steam, going up to $15 at the end of the week. It's certainly not for everyone, but if first person botany sounds like your thing, it's well worth a look.
Also, I want people to share stories of panicked fleeing through the pitch-dark forest with.