While I just flipped through it, it looks a lot like Labyrinth Lord(tm). You have the class system from there, you have the “Planet of the Apes” races and classes (well, I only know the early films, not the recent relaunch, but it is all their). As the different, ability based boni are now called “column 1”, “column 2”, etc, reading the rules is a bit puzzling. But anybody who is familiar with the predecessors will not have much trouble.
There is no magic, but a new PSI-system were a Psionic character uses up “psi points” to activate “psi powers” (usually attacks made against another being). Not a bad approach, and the number of psi powers is small enough to keep track of what might happened.
A little setting is provided as well, but the picture of the world is only painted in broad strokes. And that is alright, I guess this retro-rpg aims at us “old guys” who know the original movies and want to have a little fun with that setting.
If you look for something like that, go and get yourself a copy.