At first I wasn't totally sold on it, I disliked the fairly generic anime boy instead of the usual whimsical/weird protagonist that most of these platformer games have, the controls seemed unnecessarily weird and the ape catching didn't seem that interesting in the first levels. But the level design keeps getting progressively better: the apes start to use more tactics and are incorporated into the levels in really unique ways, add to that some really creative level themes, the gadget mechanics, and one of the best soundtracks of the ps1 and you get an extremely memorable experience.