Anticlimax Boss: General Barnaky is tougher than a normal enemy, but not to an extreme degree, and is no match for your combined squad. He's also noticeably weaker than Frank Horrigan or The Master.
Fanon Discontinuity/ Canon Discontinuity: Due to the differences between Tactics and Fallout 1 and 2, a lot of fans refuses to aknowledge this game as part of the franchise. When Bethesda took the rights to the franchise, they declared this game Broad Strokes.
Good Bad Bug: The Brahmin Armor is supposed to turn the wearer into a Brahmin; However, this only works for human characters. To non-human characters, this is treated like any other armor; in particular, this can turn the Robot recruit into an unkillable juggernaut.
So Okay, It's Average: Many people admit that, while it may not be a good Fallout game (if they admit it's part of the Fallout universe that is), it's quite enjoyable.
Mis-blamed: The game gets a lot of flack for the hairy Deathclaws which are seen as silly and canon-violating. Originally, Deathclaws were supposed to be furry, as seen in the original concept art, and the only reason they weren't was because the original game's engine wasn't capable of rendering convincing fur. The Tactics developers used the original concept both as an homage to the concept art and to show that different mutations of the same animal occurred. There are also a lot of complaints about there being real-world guns in the game even though the first two games had plenty of them (Desert Eagle, FN FAL, Pancor Jackhammer, P-90 etc.)