Aeon Command is kinda cool.
First of all, its not a side scrolling shooter at all even if the pictures make it look like one. Its like some sort of tower defense / lane defense game with some RTS elements.
You have your mothership and you need to build workers to fly around collecting resources from asteroids, to build your little army to get to the other end of the lane and destroy the enemy mothership, meanwhile using different units for different types of attacks and collecting energy for special attacks like a heal bubble for your ships, and ive seen enemies use like a aoe vortex
like I said, kinda cool (for a bundle game)