Its rabbit characters are not the interesting thing about this game. Overgrowth is interesting because this indie project from a small team has physics-driven kung-fu, destructive and satisfying swordfighting, environment-hopping wall-running, stealth, RPG mechanics, local multiplayer, and a level editor that allows you to construct your own scenarios.
The game has been in paid-alpha since 2008, a time when "paid-alpha" wasn't really a thing we understood. Now it's available on Steam Early Access. There's more detail and videos below.
Overgrowth is being developed by Wolfire Games, and the team release regular videos outlining new features. Here's a recent one showing the dialogue system and how you can use the level editor to create your own cutscenes:
The last five years of development on Overgrowth have been spent building its engine and gradually adding mechanics, so there's currently nothing of the game's eventual story mode available to play. Instead, the current build offers up different challenge scenarios, in which you might need to sneak up on bipedal rats to take them down, or fight against groups of wolves. The community have also built a lot for you to play.
It's the combat that currently makes it worthwhile. It takes some practice, but when you start to get the hang of its combination of blocks, grabs and hits, you can string together impressive, almost choreographed fight sequences. The physics-driven animation gives everything weight and variation, too. Here's a recent video on the addition of spears.
Wolfire Games previously released Lugaru, to which Overgrowth is a sequel. They're also responsible for sublime, violent, short-form indie games like Black Shades and Receiver. The latter simulates guns in terms of your interactions with them, providing separate buttons for each distinct action - removing a magazine, slipping individual bullets inside, sliding it back inside, pulling back the hammer, cocking, turning the safety off, and firing. In doing so it re-creates cinematic moments of stress and tension, as you fumble and drop bullets on the floor while trying to reload as flying, electrifying robots chase you. It's brilliant.
Wolfire was also founded by some of the same people later responsible for starting the Humble Bundle. While Humble is operated as a completely separate company, I'd imagine these bunnies to be financially secure.
Overgrowth is currently 17% off on Steam till January 2nd. People who previously purchased an earlier alpha should be able to receive a Steam key from their Humble store page. You can also buy it direct from the developer, from the Humble store, and discounted for now in the Humble Store Winter Sale.
Here's another screenshot: