I See What You Did There: Consume CULTure
I picked up this from another one of my trips to Retroremakes. It's called Consumer CULTure and it's basically an agit-prop version of Robotron, minus the guns. And, yes, I suspect I could go off on a deconstruction ala Mighty Jill Off, but I've got to go cook so you'll have to use your imagination or go and crib AuntiPixelante's. You can download it here
There's two game modes which go onto the same high-score table, so there's some meta tactics of which way to go. The first gives you three bombs to wipe out anyone near you, but you have to go and collect more up to a maximum of five (They're the little icons that look like a load of swearing). The second gives you infinite bombs (but with a five-second reload), but every time you drop you, it increases the spawn rate. Other than that, you're just running around and using the classic create-mobs and lead around tactics which any Robotron veteran will know and love. Generally speaking, I found it interesting to play a game which is half-identical to something you know, and then play it with missing some mechanics (i.e. shooting the living shit out of robots).
Also, Down With The Man!
(While you're there, you may want to get the Last Ace too, which other people love, but I still haven't had a crack at yet.)