Ok... I'm in the mood for some zombie carnage out of these which is worthy: Zombie Wonderland Zombie Escape Pro-Zombie Soccer Infect Them All (Shooting for something $0.99; but really trying not to just buy them all - someone talk me out of it)
I would go for Zombie Escape if you like line-drawing. If not, go with PZS. Or you can just go with both.
I personally prefer Canabalt to those games, due to its simplicity. So I say, YES! Especially at its current price
Canabalt and Hook Worlds are only the same in the sense that both are endless games. The actual mechanics are very different so it isn't really fair to compare the two. But if you're comparing them for the best way to spend a buck, then Hook Worlds blows Canabalt out of the water, no questions asked. If you're looking for an endless runner, however, Canabalt is definitely the best of the rest of your selection (with RUA in a very close second). I'm sure you've played the online version by now and, it's hard to explain, but it just plays really nice on the iPhone/touch. So yes, Canabalt is worth getting... just not over Hook Worlds.