I got WWG. Turns out 2/3rds of each stage are spent playing two modes of the Wii Play shooting game (not always the same two but ALL of these modes are ripoffs) with some background stuff added like occassional kamikaze guys charging you. Instead of ufos and miis you get vultures and bunnies. The shooting parts themselves aren't that long. Getting hit only resets your combo counter it seems (at least I couldn't see the health indicator in the first three stages) though you'll still want to avoid that. Would be nice if the game showed your current combo counter somewhere but I guess in games like this screen clutter must be avoided. The game has very long load times for some reason and the framerate isn't very high either. Also the company logo is a short movie, I bet a few blocks could have been saved by cutting that (and maybe the background movies that play in the menu)...
BTW, the manual is almost a complete waste of time, it consists mostly of screenshots of the menu options... If you've played Wii Play you'll probably know how the modes work anyway.