Great fun. Didn't take me that long to complete it, but worth the money all the same.
I realized while playing it that I dislike, indeed I downright hate, games with sloppy control schemes. They drive me insane. Most of RRR's mini-games have a perfectly crisp, tight feel to the controls, but some deliberately don't. Specifically, there are a couple of warthog-racing games, and a flying game or two, where your mount has a sort of inertia and doesn't respond immediately to your input. That's on purpose; a galloping warthog doesn't turn on a dime. But I found it frustrating, all the same. Later on I relaxed and started consciously compensating for it, which helped.
Still, that was an aberration. Mostly, the thing was just plain goofy fun. My favorites were the first-person-shooter scenarios where you run around with a plunger gun and a chain, snaring and shooting rabbids as they jump you. Unlike most FPSs, your character follows a predetermined course through these mini-games -- you don't control your position or point of view, you just react as the scenario proceeds. It was great, but without putting it down in any way, I'll add that I'd pay real money for a true FPS with the same concept -- Quake Rabbid, if you will.
The rhythm games on each level, in which you shake the Wiimote and nunchuck in time with a series of songs (increasingly complex, of course), were also a lot of fun but were almost too easy to enjoy. Almost, but not quite. As it was, I enjoyed them tremendously.