I have different opinion in this subject. For me TF is very good game, great for party, You can play it in coop or death match for four players. I like arcade feel of this game, action took place on one screen, there is lot of small details like hero avatar on status bar or well animated objects that can be destroyed, You can destroy nearly everything in this game and it feels great to watch how those small tanks eradicate entire town, or train yard, or some fortifications. game also require some brains, You can not spam bullets and need to think when shoot and when change Your tank position. There is hype because game is fun to play, that's all
If Zerosphere or Moebius were commercial games I would buy them too.