LMMS
LMMS combines a step sequencer, piano roll, automation, synthesizers, samplers, and plug-in support for game loops and prototype scores.
Why use it
It is fully free and cross-platform, giving beginners a path into MIDI- and synth-based composition without buying a DAW.
Where it fits
Use art, animation, audio, levels, and narrative to make the game easy to read and its world convincing.
What to check
It is not centered on multitrack live recording, and detailed audio editing, mastering, or very large projects may call for another DAW.