Excellent game! I loved the atmosphere of the game. The story was a good one as well, had me hooked immediately.
Like others, I found the wall jump to be a little clunky. With some polish though, it could be an excellent stealth game.
I did find an issue where I died after getting the grappling hook and it took me back to the beginning, but didn't respawn the hook, or let me use it. I had to restart the game to get it back.