Avernum 6 is a superbly designed game, one of Jeff's best. He really got the sandbox gameplay down to a science and it shows. I'm tempted to write a review because I'm sure that many people look at the screens and go "Money for THAT? You've gotta be kidding. An autistic 8 year old can draw better doodles".
To put it simply, the game is fucking awesome. If you like sandbox games, download the demo, because it's THE best sandbox game ever. It's better than my beloved Daggerfall, it's better than Gothic 2, it's better than Morrowind, it's better than Risen. The graphics are one step above ASCII, but the gameplay (fucking everything, from loot distribution and battles to dungeon and quest design) is top notch. 10/10.