Not bad
You could of added more categories for the Bridge, knobs & switch(s), tuners, width of the neck, wood used for the body and neck, fretboard scale (21, 22, 24, 27+ frets), and even accessories such as: a strape, case and picks. Most people would probably not knowing anything about those items but if your going to make a custom guitar game like this and you want to make it amazing, you should just add those items for the extra nice detail points, but guess half of the stuff I mentioned wouldn't be even visible from just the front side view being shown in the game, which brings me to add that there should have been more views to see the guitar from (side view, close up view, back view.
I was disappointed to see so few headstocks and bodies that I had a choice from, even though I only like Super Strats anyways. You should of added some features from Jackson, ESP, Kramer, Carvin, Charvel, Edwards, Dean or even Music Man, I would say more but that's all I can name off the top of my head at 1AM in the morning. Most of those guitar companies have a lot of great looking inlays and bodies that would have added a lot to the game. You could also add amplifiers such Marshall, Peavvey, Vox, Fender, Krank and so on. And also there are people who are left handed so you might want to think about that (Left handed people = Left handed guitars). And there is no such thing as a white or black fretboard :P but there is Rosewood, Maple and Ebony fretboards. Also, you could add a counter that adds up the cost of all the stuff. OH! and you could add an option for 7, 8+ string guitars. Yeah, I'm a gold mind of suggestions for you haha. Alright, goodnight.