Zack & Wiki 2
A better name.Seriously, Zack & Wiki: Quest for Barbaros' Treasure is an awful name. I'm not joking when I say I think it would have sold a lot more if it wasn't for the horrible title. Why not just Zack & Wiki? I didn't mind the name, but a bad name means less sales, which means less money, which means smaller chance of a sequel being developed. Just drop the stupid subtitle and call it Zack & Wiki 2 - it's short, it's simple, and it doesn't sound awful.
Variation.The variation of environments and puzzles was definitely one of Zack & Wiki's strong points. You'd control mechs in a volcano area, mix potions in a madman's laboratory and then fight a giant ice lion in a frozen room. Maybe it's a bit much to ask for, but I would love to see as much variation in a sequel as there was in the first one.
Great motion controls.Zack & Wiki implemented motion controls without ever making it feel forced or tacked-on - in fact, I couldn't imagine playing the game on a PC, without motion control. You moved by pointing and clicking with the remote, but there was so much more. You'd pull levers and answer phones by simulating the moves with the Wiimote, shake Wiki(you know, the yellow monkey who turns into a bell) by shaking your controller, and much, much more. This is what the Wiimote was made for, and it's sad to see that not many games manage to get it right.