But- they half assed- just about every feature- and never returned to 'em o_o
They added a few good things- like having passive mobs run when hit which allows it to be more immersive (except they run randomly instead of away from you). But as much as people wanted wolves, those buggers are better off dead, the moment you tame one, it will do everything within it's power to either kill you, or kill itself. lol
But relating to immersion, the binary weather (on | off) and swamp biomes- can break immersion immediately, at which point you're not longer playing the game, you become self aware that you're just some guy sitting at a computer trying to enjoy your lonely life. :[
Also- I hate invisible walls, worst thing you can do to break immersion. Glad minecraft doesn't have those.