From my point of view Procyon is the greatest shmup on steam because it has got no flaws at all.
It offers a highly enjoyable coop mode, beautiful, sharp graphics and great lighting effects. The amazing orchestral soundtrack uses one characteristic and short motive in all stages.
Even the hilarious background story is thought provoking and really well written: " We are humans, we're REMARKABLY GOOD at fighting and we fought back / Unfortunately, we're humans. We are REMARKABLY BAD at ressource management!"
This game for this ridiculous low price deserves your attention. It's deeply accessible, features easy / hard modes and therefore it will please casual players and even veterans.
I can't praise enough the hard work of Josh Jersild, the developer of this little gem.
This guy did all the programming, the hilarious voiceovers, the great score and the modeling / texturing ON HIS OWN in his spare time but this game that easily stands out from the rest doesn't feel like homebrew.
Just check the other reviews on the store page! This tasty, delicious cake can hardly be a lie!!