Hoo boy! The recent Halloween update is certainly dividing opinion on the Minecraft forums!
I downloaded it last night, and with it came biomes (mini climates that I'm excited to see further developed), an underworld (with new enemies and blocks/materials) and a fishing mechanic.
Unfortunately (this is where the butthurt comes in) it came with some very serious/irritating bugs including armour that doesn't work (it doesn't matter if you're butt naked or wearing full diamond armour, those pigmen are going to ruin you just as fast) and an odd bug whereby - on death, your items disappear from the world altogether - you can't return to you point of death and pick them up again. Furthermore, mob spawning seems to have been ramped up - handy if you want to slaughter 100 chickens in an in-game morning for their feathers - not so handy if you want to make your way through a cave, and find yourself battling a crowd of zombies, skeletons and spiders along the way.
The portals that transport you to the underworld are also confusing in that you create one, enter it [into the underworld], and when you exit back to the overworld, you end up in a different place - despite using the same portal.
Finally, there seems to be a few glitches including monotone sprite animations (animation of leaves being destroyed), grass surface not matching the tone on a side of a block, and leaves not disintergrating on their own.
And Survival Multiplayer hasn't been fixed, although at this point in time, I could care less.
My personal feelings are that the combination of ineffective armour and losing all your items on death (the former being THE worst of the two) are what spoil it for me, but I'm confident an update will fix these issues and look forward to how the developer can improve on these concepts over its development. In particular, I'm looking forward to more defined regional resources and effects (maybe rainfall and heat damage).
It is an alpha after all...
[EDIT: also, some people are having performance issues and program crashes]



