Lots of fixes, some additions, focus on the zombies mostly if you can. The collision with cars is turned off for now (zombies animals), we need a bit more work on it. Zombie models are gonna change in 0.56 probably. There is some small visual stuff (like the running up attack missing), so the zombie weirdly stops as he gets to you. Has some weird interaction with ladders etc. And some more visual/gameplay stuff. The new loot system is turned off until we get the bug fixed. Might get on stable.
There is lot more work to be done, for zombies to move and chase you on ladders, windows, destroy doors etc. There is no group AI , nor there will be for 0.55. But the basic stealth is there and the performance seems to be really good.
There will be more experimentals over the next few days. The target for stable is 25th. With a small chance of being pushed to 1st if we dont get the last critical bugs fixed.
EDIT: Also one annoying bug, if the zombie is chasing you and gets stuck in collision with terrain on client, it does not update properly and there will be an "invisible zombie" chasing you. If you want to avoid it, try to kill them or dont aggro (stealth around!)