I had an idea for a Space Invader moveset awhile back.
Basically it's Space InvaderS, so it's three at once, those being the three different types of aliens from Space Invaders. They fight together like Banjo & Kazooie or Duck Hunt, so no Ice Climbers or Pokemon Trainer-esque gimmicks. Their lightweight and have multiple jumps like Kirby, but have really good air mobility and have alright falling speed, but ridiculously quick fastfalling speed. Think Yoshi with Fox's fastfalling. This gives them excellent mobility but to compensate, their attacks are pretty weak and they have trouble KOing. As for the moves themselves, they'd be similar to Duck Hunt or Mr. Game & Watch or PAC-MAN, where they'd draw from other Atari games for some of their moves. I remember one of their smash attacks crushing an asteroid from Asteroids, sending debris around that moves slowly but travels really far, if that's any indication.