Audacity
Audacity offers multitrack waveform editing, recording, noise reduction, loudness processing, effect plug-ins, and macros for dialogue, ambience, and short effects.
Why use it
It has no subscription, extensive learning material, and dependable everyday cleanup and format conversion for indie projects.
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 a complete composition DAW or adaptive game-audio system; complex mixing and runtime behavior need other tools.