If you haven't played this yet do yourself a faour and grab it quick! It's super fast retro insane high speed mega blasting at its finest. It's a clone of the XBox's "Geometry Wars" but it's much better! It's so good that the author's had to remove it from his web site so download it quick while it's still available... 
Read this review:
http://worldofstuart.excellentcontent.com/grid/wars.htm
Download here:
http://www.download.com/Grid-Wars/3000-2099_4-10532890.html
Read this review:
http://worldofstuart.excellentcontent.com/grid/wars.htm
Download here:
http://www.download.com/Grid-Wars/3000-2099_4-10532890.html