Caveman/YMMV

Designated Hero: Atouk comes across this, yes he was being bullied and used as an unsafe food tester; but then there's the Victim Falls For Rapist instance below (which indirectly was the cause of him being banished), and his attempt to kidnap Lana. There's also the Yandere behavior on Tala's part.
Ear Worm: The campfire song when they invent music.
Hilarious in Hindsight: Lar becomes frozen on ice on the "Ice Age", more than twenty years later he would be fighting another ice age.
Hollywood Homely: Tala.
Special Effects Failure: The giant mosquito. Even on YouTube the rotors of its wings are clearly visible. The Pterodactyl also hovers in the sky, not gliding nor flapping its wings. Any time a stop-motion human is riding or being eaten by a "macha".
Unintentionally Sympathetic: Tonda is the bad guy, and he's a jerk ass... but at least he's looking out for his tribe, and he was also shown to be genuinely upset when he lost Lana to the river (despite that because of his status he would be able to easily get another mate), so did he really deserve the beating (and possible death), he got in the end?
Visual Effects of Awesome: The film was well-financed, having two Beatles attached and all, and it shows in the special effects. While you can tell where they blocked off the shot to allow for the matte of the horned lizard and the T-rex, the stop-motion effects on them are quite smooth and the lighting matches well. Not to mention that they were designed to look real but cartoonish to match the whimsical humor. The T-rex is so well animated you really get the feeling he isn't mean, he's just an animal hungry for people is all.