Never said "duck" so much in my life
The gameplay is good. It reminds me of early classics like River Raid and Moon Patrol.
I was somewhat confused on the race stages; with the exception of the champion battle, there was no interaction, so I didn't quite understand what was going on at first. Still, the races were fun to watch.
Once you max out your energy, though, the need for coins vanishes. Not sure what point they have otherwise?
There was a bug in some of the swimming stages: you could double-bob or air-jump unexpectedly.
By far, my favorite part was the funky music played in the advanced training! Where can I hear more by the same artist?