Procyon is a very good indie 'shmup that fans of the genre should enjoy.
As a fan of these type of games, I judge them on 3 main factors. First is it's "uniqueness". One of my favorite shmups/bullet-hell games of all time is Ikaruga b/c of how it took a classic game formula and twisted it and made it something new to play. This is probably one of Procyon's biggest drawbacks. There is not much to seperate it from other side-scrolling games of its ilk. This is not to say it's a bad game, on the contrary. It just doesn't do anything differently. The second factor is control. Games like these require tight and precise controls especially when the going gets hairy. Procyon has controlling down pat. I was able to jump right in and was able to pilot my ship and not once have I been disappointed by the controls. Thirdly, is fun-factor. Procyon is a fun game and has the right level of arcade challenge to keep me wanting to retry immediately when I fail. A good way to describe this game is a "meat and potatoes" shoot-em-up. I would have liked to seen more variety in weapons, but Im also not incredibly far into the game so that may change.
This game is definitely one that can be defined as "indie" in respect to looks alone. The design is very simple with ships not having a whole lot of pizazz or graphical oomph. I don't play these games to be wowed by graphics, so this is a minimal knock for me, but others that judge games purely on looks will probably not find much about Procyon. Lighting is well done and when there are a lot of enemies on screen with different colored beams going off its definitely eye candy. I also liked some of the stage backgrounds i.e. Empire City. Nothing extraordinary, but eye catching and adds to the level. Enemy design is mostly simple, and there's a particular enemy that looked to me like a Playstation controller. Whether this was intentional or not, I don't know, but its something that caught my eye.
A very strong aspect of the game is the soundtrack. I find soundtracks in games like these to be more important than in other genres and Procyon's music to be excellent. A AAA developer would be happy to have this quality of a soundtrack in its game. The fact that it's in a shoot-em-up makes me very happy and will keep me playing.
Steamworks integration is very much appreciated. With card drops and achievements, this will add to the game's replayability. I love the fact it tracks high scores as well, as I consider this to be a staple of this genre.
All-in-all I recommend Procyon most especially to 'shmup fans. It's a classic side scroller and does pack a challenge as you go further on into the game. The music is awesome and adds to the gameplay experience. I also think that it's $3.99 price point is pretty much right for a game like this.