Teenage Zombies is a 1959 horror film. Reviews of this one are scarce.
Slow. Incredibly, painfully slow. The choreography of the fight scenes is slow. The dialogue is slow, with responses lagging. Oh, so slow. And the teen actors seem not to know quite what to do with their hands. There is a lot of posing.
On the other hand, there's a gorilla.
The Internet Archive has this available online, if you want to bother, but, honestly, why?