It's all in japanese, but with some patience and luck, you will find many BRILLIANT Japanese free/shareware games.
An alternative is going to http://shop.himeya.com
, and check the games for sale. Most times they include a link to the creators' homepage where you can download a demo and many other games
Right now I'm playing a VERY adictive beach volley game. it's the Demo version, though. Still mega fun