"Despite the couple of annoyances about Hidden Path's Defense Grid, I found the game enjoyable and addictive. Many nights, I've hopped on to play one or two missions, but stayed for five or six just because I was curious what the next map would look like, or what it would unlock. For the achievement-whores out there, there are plenty of Steam achievements to be had with easy challenges such as saving up a certain amount of resources by the end of the map, to harder ones. For tower defense fans, Defense Grid for $20 through Steam is a no-brainer: it's polished, the graphics are great and run fine on my 4 year old PC, the music gets your heart pumping, and it's just plain fun. Sure, there are plenty of capable tower defense flash games out there, but with Defense Grid, you get tower defense, a decent soundtrack, and nice eye-candy while you're playing."