Azaratur: A tracker is a good option, but can be a little confusing if you have never used one. With a tracker, you can easily do the type of music you hear on a NES as well as music you often hear on a Playstation 1, PSP or Gameboy. Using samples in a tracker is pretty easy. Setting up instruments isn't that hard too. But you often feel that, in a tracker, you program your track more than composing. I find it particularly entertaining to code music in a tracker. Tracking makes you do music that you might have tought complicated at first listen, which is a bonus.
But if you want to make orchestrated music with complex notation, you're better off buying a midi/usb controller keyboard and try Cubasis or another one of those midi programs. I remember long ago I was using PRO 24 and found it quite inspiring for composing ambient type tracks. I foudn Cubase pretty practical for composing drum sections.
The bonus you get from using midi is that you can then save your midi and play them back fairly easily. Yet, your track might sound different depending on the sound card one has. For that, you could probably find a way to render your track as a WAV and then convert it to an MP3. The problem is pretty similar for tracked music, as you will either have to make sure the language has the right tracker playback system and that it doesn't crash your running game. Or, you could render the tracked music as an MP3. Some tracker are fairly oipen and accept VSTs so you can play your instruments with interesting effects hooked to them. One ongoing project which I have an eye on is OpenMPT, but is fairly buggy, yet has some excellent features. I think Milky Tracker is also good, but I have little experience on it. Another tracker, but more complex is Renoise, which is excellent for it's sound quality.
finally if you feel adventurous, you might want to look at Reason, yet it is pretty expensive and complex to use, but very powerful.
http://en.wikipedia.org/wiki/ModPlug_Trackerhttp://www.propellerheads.se/products/reasonhttp://www.computeractive.co.uk/personal-computer-world/software/2043592/steinberg-cubasis-vsthttp://chibitracker.berlios.de/http://www.renoise.com/