Do you like Banjo Kazooie and DK64? Walk away. This game is not for you.
Have you ever played a platformer and thought to yourself, "Why do I have to collect all this crap?" Quite simply, it's because it drives the game forward. In Banjo Kazooie, you need to collect the jiggies because without them, you can't open new worlds. If you didn't need to collect them, you could just go to each world long enough to learn the new techniques there and then go straight to the final boss.
Conker's Bad Fur Day, on the other hand, doesn't make you collect any items to open new worlds. You just have to do a puzzle, and boom. The new world opens. The only collectible objects in the game are piles of money, which, like jiggies and golden bananas, often require solving tough puzzles. But unlike the other two, the money doesn't actually do anything. You can go out of your way to collect it, but you're wasting your time. You don't use it in the game, and it doesn't unlock any extra features.
Another problem is that there isn't any direction whatsoever. After you finish the first chapter, you're left to stumble around until you figure out what it is you're supposed to be doing. Don't worry about missing hints in dialogue; THERE ARE NONE. It's easy enough to find your objectives once you get them (objectives which, again, seem completely pointless considering there is no actual reward), but the real problem is finding someone to give you objectives. The story provides no hints as to what you should be doing.
The controls aren't terrible, but they aren't great either. You only have one attack (yes, one) the entire game, excluding the parts where you're transformed as part of the story. Most foes you're either expected to just dodge completely or defeat in a situation-specific way. You're a weak little squirrel, and the game doesn't let you forget it. It's like if all the goombas and bob-ombs and whatnot in Super Mario 64 were never intended to be fought, just avoided.
If there's one thing this game does right, it's the humor. The crude humor will give you some guilty pleasure, and the dialogue and voice acting are priceless.
This could have been a great game. Hell, it SHOULD have been a great game, considering who made it. But the pointlessness of performing tasks, the lack of direction, and the almost nonexistent ability to defend yourself make the entire game seem like a forced experience. The bottom line is that it doesn't draw you in, and it makes no attempt to keep you playing. If you want to make it all the way through this game, it will have to be entirely by your own self-motivated efforts.