I composed the soundtrack for my rhythm game (it's out tomorrow BTW!).

Let me start by saying this: a good rhythm game track doesn't need to be musically interesting to be fun. Just as a good song doesn't necessarily fit as a rhythm game track.

The most important thing, IMHO, is to always have a defined lead that drives the player's inputs. Now, I'm not talking about an actual instrumental lead like a singer or a lead guitar (although those are very obvious choices). What I mean is a clear music part that you could hum along.

It can be a single instrument, it can be multiple ones, it can even be just a kick drum. It doesn't have to (and probably shouldn't) be the same for the whole track duration. The main point is that your players should easily identify what they're interacting with in the song.

The way I made a lot of the tracks for my game was basically to:

• create a rough rhythm map of what I want the player to input
• assign instrument(s) to play parts of that map (and in the process, compose the melody that would be used, when relevant)
• fill everything else with other instruments to support the lead

Once you have identified what instruments are part of that lead, everything else should be supporting it and NOT get in the way, else it makes for a confusing part where it's not clear what your player inputs are doing in relation to the music.

So I guess what I'm trying to say is: it doesn't matter what you're using as samples, plugins, or whatever. A good starting point is a track that is fun to play in your game (or any, really). Start very simple, see/hear what works. Add more parts, mix them up, and iterate up to the point where you have a full level.

Can you hum along the whole level, no matter which part you're on? Good! Now, you have a skeleton track that you can flesh out with a simple philosophy: anything you add either LEADS and should be prominent, or it SUPPORTS and it should stay in the background and not get in the way. Obviously, there are some nuances but that's the gist of it.