Retro/Grade is a well executed mash-up of the Rhythm and Scrolling Shooter genres. When I first started the tutorial I was expecting to be playing (reverse) Gradius to the beat of an awesome soundtrack; But instead what I got was Guitar Hero executed in a way that I had never thought of: To keep the music going while avoiding enemy fire!
The graphics on the game are very vibrant and the colors perfectly compliment the 2-5 lane system. Each lane uses the same color coordination as all the well-known plastic guitars out there for other rhythm games; Not only was it a blessing in disguise to be given something so familiar to me within the genre, but the mixture of colors on-screen from all the attacks made a fantastic light-show! Sometimes the screen could get cluttered with different colors and certain attacks could get very hard to see through all the explosions and other effects on screen, but with enough practice with each level has a pattern that you can follow or sometimes predict to compensate for this problem.
The difficulty scales from "So easy that it's almost hard to play" all the way to "There's so much going on I don't even know what to do!" I found myself preferring the X-Treme difficulty not because it was harder, but because all of the shots felt perfectly in-tune with the music; However, the lower difficulties did well at teaching you how the game works and allowing you to easily learn the system to advance to the next difficulty. The biggest grace about playing on X-Treme difficulty is that with so many more notes to hit every one shows you the route to avoid enemy fire, so I was able to focus more on what I needed to hit and less on how I was going to find the path to hit it.
Also: It's interesting to note how much each level changes to accommodate the new difficulty level. When adding another lane to play on naturally you would need more enemies on screen, but what really shined were the boss levels and how their interactions and patterns changed, making the replaying of each level feel less of a chore and more like a new level all together.
The controls are super simple on both the controller and guitar (I never tried it on keyboard nor had any intentions to do such.) The A button is king and has many different uses based on what's coming at you. From holding it down to fire a beam, to rapidly mashing rockets, to single-fire shots, one button is all you need to take on all the levels. On the other hand, if you've got a plastic guitar handy, this game can really show off your skills. I actually found it more challenging to play the game with the guitar because you have to incrementally slide everywhere to avoid getting hit from behind by enemy fire; It almost feels like you're playing two different stages at the same time in this game because you have to slide from lane to lane avoiding enemy fire and at the same time make sure you're in place to hit the notes coming at you from the other side.
To be honest, I'm good at playing the Guitar when all that's coming at me are notes and I just have to get the timing right or at least memorize the song, but this game actually went beyond my current capabilities with the guitar and that concerns me. I know it's fully possible to beat on the highest difficulty and most likely has been done by someone at least during testing, but I feel that when a rhythm game is more easily played on an xbox or ps4 controller than on a controller specifically made for use with rhythm games, something has gone wrong. I've tried playing Guitar Hero with a PS controller… it was almost impossible for me at higher difficulties. This game feels exactly the same way just in reverse (Hah, almost ironic when thinking about the game's story.)
If you're a fan of rhythm games and want to try something new: This game will fit quite well in your collection regardless of your skill level with the genre. The price is extremely reasonable for the game. (Plus the soundtrack to the game is amazing!)
However, if you want the game because you can use the guitar controller to play it (or even if you just like the space-shooter aspect of the game), I suggest you pass this one up for something that's more of a better fit to your skills.