I noticed a mention of this in the copyright infringement thread but it's worth a mention here too.
I really like Jydge. It's a top-down twin-stick shooter that has a bit of a 10p Judge Dredd thing going on but after a while that doesn't really matter. The main thing about it is the rogue-lite elements and the really good upgrade system.
And more importantly, the brilliant level design. That's where it really impressed me. The levels are so tightly designed, especially on harder difficulties.
Worth a look if you see it dirt cheap in the PSN sales one day.
Robokill (https://www.miniclip.com/games/robokill/en/)