Moody, tense, and atmospheric, with just a touch of humor and some really, really, odd-sounding American accents. This is the earliest existing Cybermen story thats fully-intact, and its really good. You have two sets of villains in the form of the Cybermen and the Logicians. You have some great set designs. You have some really decent SFX for the time and the budget. Importantly, you also have a really well-written story with some great dialogue. Theres a wonderfully touching scene where the Second Doctor is talking with Victoria, who had just joined the TARDIS crew after some of her family were killed by Daleks. They have a great conversation about loss that shows what the show as really capable of back in the day.