Ripple Dot Zero I have got to say, of all my years just going on Newgrounds every once in a while just to play a game to pass time out of boredom, I did not expect to find a game that had a soul. What I mean by that is this game right here has an incredible style to it that you can't find here anywhere else on this site.
Graphics: The detail to sprite work and animation is astonishing. The levels have a nice immersive feel to them and have a sense of being lost on another world. The enemies and their color palettes remind me of something from an 80's or 90's Sci fi alien art you would see in a book full of concepts from what people imagined the future would be like in those days. As a artist myself, you did a phenomenal job with what you have here, it is unique and would like to see what style you create for your next game.
Music: It's catchy, it's peppy and atmospheric, it reminds me of Amiga or 16 bit console games. That's all I can really say, you nailed it and whoever composed these tracks did an amazing job with it. I might have to search for an OST of it.
Gameplay: Obviously the most important aspect here. In other games, sometimes exploring the levels or playing a level again to find everything would be tedious and annoying. But here, the controls and feel of the game is so fun and spot on I didn't even complain when I failed a bonus stage multiple times and had to replay the level again just to try again. The power ups are fun like using the jet pack to gain momentum in the air to get to secret areas just feels satisfying as well as using the disc cutter to destroy enemies and collect pills. While the game didn't change up later down the road and while the game didn't have many boss fights including epic difficult ones, I still enjoyed it.
Verdict: No game is perfect, but then again what is? This is what I have been waiting for a while, somebody who cares and puts a lot of effort into what they love and to you, it's making games. I suggest you make a update version of this game with more levels, maybe a bit more gameplay variety and more bosses and put it on Steam for around 5 to 10 bucks. I think you will do a good job.
Going to give you a 5 out of 5 because of how much I was surprised I loved the game and how it might inspire others on this site and independent gamers to try harder.
Game Corp 
Binding of Isaac DEMO