Personally, I don't understand what the point is. I get attack and release, but the ratio aspect does nothing for me. (FWIW, I work in a field where I need to compress live vocals, NOT a recording studio.) I'd much prefer a game where I need to manipulate threshold and ratio.

This video helped me a lot to better hear compression:

Robbie - search how to hear compression in YouTube - there are a bunch of good vids - check House of Kush.
If you want to go deep - mastering.com channel has a 10 hour compression video on YT.

Ratio is the amount of compression that's applied once the signal passes the threshold. for example a ratio of 4:1 means that for every 4 dB of audio that passes the threshold, only 1 dB comes out. The game compressionist allows you to change the threshold so that's good practice. Also the higher the ratio, the more squashed and unnatural the percussion instruments will sound, however a slow attack time can just make it sound punchier

@Robbie Parkinson You should try using extreme compression settings on a compressor in your DAW to see if you hear anything then. Use it on a drum loop or something (drum loops help me the most anyway). Shoot me a DM if you wanna talk about it more.

The way you understand compression expands if you learn to use some synthesizer like serum and learn to play with the ADSR controls everything becomes easier. I'm not an expert, but one of the things you can look at is how the initial hit of a sound changes (of a kick for example, when you compress, the timbre of the kick can be altered) or how long it lasts. keeps in comparison to the raw signal, and how the tail sounds, the end of the sound. You can also notice how it frequently changes bass, mid and highs. It's a matter of practice, trial and error in the end. Greetings :)!

I find that lowering volume to almost detectable is a good way to hear compression. Are all instruments audible and more consistent? Are snare hits more consistent?