Van Hemlock.com

Been playing this for like an hour a day over the last 3 days on xbox live (it's 400 points). It's basically a puzzle game with IQ-test type puzzles.

It's a little annoying at times, took me a few goes to figure out the controls on some of the 'tests', but once I got them they were fun.
It's also a little confrontational at times when it tells you, you suck -well it gives you an 'F' but still- for example scoring D's and one C of the past three days on the logic test wounded my pride a little :'(

It has a bunch of training modes and then the 'daily' test (which you can do endlessly regardless) which cycles you through 5 different brain tests al having to do with a different brain functions in succession and calculates a score at the end. The idea is you do it every day so you can see your progression over time!
Notably it has also given me 5 different test over the last 3 days so it would seem it's setup so you don't 'get used' to doing the same tests (it knocks you out of your comfort zone).

It surprisingly addictive and quite a bit of game play for 400 points, slightly lacking on the documentation and instruction part however (controls are ok once you get used to some of them).

There is a free demo too that gives a fair impression imho Smile Had my 400 points worth of fun out of it already and there's still a bunch of modes I haven't even tried yet! I think it deserves a look at the demo at least if you have an hour or so to waste!

http://en.wikipedia.org/wiki/Brain_Challenge