As mentioned, there are only two levels on this one Beginner and Advanced. I really wish I knew why they limited this great activity to just two rounds, but oh well. Again, that is my biggest slight on Obstacle Course...simply that there is no expert or 3rd round. That should, however, speak volumes for how great this exercise is. While you get a good workout in, you have a ton of fun, and that is exactly what Wii Fit Plus' Training Plus aimed to deliver.
The Obstacle Course on the Beginner level is fairly straight forward. You run, jump, and avoid obstacles that would send you off the course. Granted, each time you get knocked off you simply start over at the last cleared segment. It will take awhile to master, but once you first hit that finish line it won't be long until you are crossing it quicker and quicker each time out.
The Advanced level is a bit more demanding. You have the same series of challenges, but there are some new ones as well...most notably ice! The ice is slick and your Mii will slide across it...and off it (as I so elegantly demonstrated, lol). The basic concept is the same though, master the course and improve your times. Once you have established a good time you will have to contend with trying to best it...this is usually catch 2-2. Your judgment tells you to be safe and wait, but your record hungry side says to go for it...you'll either make it and ascend to new heights or be knocked off and lucky to place in your Top 10.
The Obstacle Course is a ton of fun and has great replay value both for record seekers and casual players alike. It did exactly what the designers intended...get you active and make sure you have fun while being active!