These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Base Breaker: Dan. Is he a stern teacher that's just frustrated with Gen's hotheadedness and only wants to help him become a true hero, or is he an abusive bully who torments Gen for things that are out of his control?
Another side of this is that Dan may be more frustrated with his current situation: He's powerless to stop possibly one of the most aggressive waves of kaijuu ever, his men are constantly outgunned and being killed off left and right, and the only thing he has for backup is a hot-headed rookie. Of course he's going to project this on Gen as (sometimes) unreasonable expectations.
Episode 29 came out of the blue, has nothing to do with future episodes, and it brought no closure for Dan. It was just a case of Mistaken Identity.
Complete Monster: Commander Black wants to take over the Earth, and he'll do whatever it takes to do so. He actually kills off the entire MAC group except Leo in his first appearence! He manages to top himself later by slicing Leo into pieces alive (Ultraman King revived him but still!) and using a little kid to force Leo to let his final monster beat him down. Needless to say, when he gets beaten to death by the kids Gen trained to defend themselves, its well deserved.
Bunyo would put humans in jeopardy to ensure Leo's capture.
Tsuruk was just ruthless and violent.
Crazy Awesome: That MAC team member from Episode 12, the one who looked like a homeless man. He was very lucky...