The TL;DR version is a board game version of Ape Escape, cause why the hell aren't they still making these games? Also tell me the closest existing board game to this idea.
2-4 players.
Probably competitive but without much direct attacking of fellow players. At worst, a way to steal gadgets from each other. Wife does not like direct confrontation in games.
Randomized board via tiles. Some combination of Betrayal at House on the Hill, other exploration games.
Movement and actions for players controlled by individual decks of cards, with some always being available(i.e. basic movement and the generic net capture). Other, better actions/gadgets found when capturing the primates, or exploring a new room. Draw 5 of your cards, but can only play 2 or 3 in a turn. Some go back into your deck, some are 1 shot, some are passive and stay in play, like a speed upgrade, or a net trap in a room.
Primates themselves are revealed as you explore, will have basic type that decides AI movement/actions, with semi-random upgrades. I.e. chimps are fast and tend to run away. An upgrade might be dropping a banana peel when they leave a room, or extra speed. A large gorilla might pursue players aggressively and be immune to the basic net.
The general idea is not every primate will always be capturable with your current equipment, so if you see there's a few particularly fast monkies, you'll go out of your way to get an upgrade to help you catch them. There are only so many rooms and primates available, so games should play relatively fast, but offer a lot of replayability via the random layouts and upgrades.
The overall tone is meant to be silly, slap-stick style fun. If you've played the ape escape games, it's exactly that.
Edit:
Now is when I need everyone to tell me I'm an idiot, and that doesn't sound fun at all, so I can stop thinking about this.