Rhythm Heaven Fever is a procession of adorable cartoon situations. A boy kicks away stray footballs that threaten to ruin his date. A quartet of baby seals tilt back-and-forth in marching-style unison. A tiny monkey taps a tambourine, its big brown eyes gleaming with joy as you repeat its patterns. The game's energetic sweetness is the antithesis of this console generation's characteristic gravelly machismo and brooding drama. It's pure joy.

And yet, it wracks my nerves like a Counter-Strike match. My palms sweat as I constrict the Wii remote in a boa's death grip. My heart races before I even select a song. Like a tiger crouched in the brush, I await the right moment to strike each note with parched eyes. Even with the peppy rhythms as a constant guide, relaxation is a shortcut to failure.

You can't get careless because the game demands total precision. Guitar Hero understands that you have five frets to manage and cuts you some slack if you're a split-second early on the downbeat. Rhythm Heaven Fever scrutinizes to your timing to the millisecond: near the end of the following video, the song approaches 180 beats per minute and splits each beat into 23 blocks; I am tasked with hitting only the center column. There is no room for error.

The smiles and rainbows are a front, as the cute chimps and happy cheerleaders of Rhythm Heaven Fever know exactly how well your internal metronome is running. And they are judging you. Harshly.