Resogun was a pretty fun indie twin-stick shooter. Really captured the feeling of chasing high scores on Galaga in the roller rink arcade. I played it for free when it was a PS+ launch title for the PS4. Didn't touch it much again after getting through it in that first month or so. I have no idea what it costs outside of that, but if you can get your hands on it for dirt cheap or free it's worth a few hours of your time.