Space Invaders Get Even to invade your wallet

Defending 3D cities from a wave of 2D retro baddies in Space Invaders Get Even sounded pretty cool to me. But, after hearing of this pricing scheme, some of the Do Want-ness has worn off..

Game|Life says that although the game is priced at 500 Wii Points ($5), you'll have to pay that much for each of the four levels, making the total package $20. 

To be fair, I haven't had a chance to play Get Even yet. Game|Life seems to dig it after playing a bit of the Japanese release, but says that the thrill didn't last that long:

Unfortunately, my $5 went rather quickly -- it won't take very long before you've finished the first set of three levels and the game gives you the modern-day equivalent of "Insert Coin To Continue."

I love the ideas behind this game, but I don't love the pricing or episodic release structure. What do you think?

[Thanks, Andrew B.]