listen for how forward or back the kick and snare are in the stereo image. faster attack times sound muddy and distant, slower attack times sound close and in your face/ punchy. Use good monitors or studio headphones. good luck!

I only use HD drums, so everything I'm saying is geared towards that

also, short release times = distortion and 8:1 ratio also starts creating distortion, once you get into the further levels.

At early Level, What im hearing is that because the sound is compressed, the transient sound feel quieter, and even change slightly its tone to a lower note ( mind trick ), so i usually based myself on the Kick Drum or Snare Drum ( mainly ) so you can hear it correctly.

if it happens that the two Snare or kick from each signal are at the exact same level it means that they added the output level now, to which means that now, on the compressed signal, the quieter part is more prominent.
So in this case, if the two transient sound on each signal are a the same level, the one that has the more tail sound is the compressed sound.

Try this, this has been working like a charm so far

Each sample play typically consists of two sounds. In the earlier levels, the compression ratio tends to be quite high, making it easier to compare the dynamic range. Dynamic range refers to the difference in volume between, for example, the drum and the shaker. If the shaker is very quiet and the drum is loud in the first take, it’s likely that in the second take, the drum will be slightly quieter and the shaker slightly louder, resulting in a reduced dynamic range aka more compression.

I might suggest that the punchier sound is less compressed - though this isn’t really technically accurate at all, it might help guide you in the right direction during the initial levels.
I personally struggled with this game until I learned more about compression. Without an understanding of compression, you might notice differences in the sounds but find it difficult to identify which one is more compressed. Probably best would be to find a tutorial and play with a compressor in your DAW - just to understand what it does.

Maybe that helps a little bit.

I struggle with this one as well. I went to YouTube and watched 4-5 videos on How to Hear Compression and it REALLY helped. The House of Kush had a great one.

In comparison where the ratio is the same or close I hear different Attack values as tighter for higher Attack and Looser/washier for lower Attack. Ex at an 8:1 ratio a loop with a 10ms Attack value will have a much more open/looser sound than the loop at 25ms. Also check out the Compressor video on Mastering.com. It is free and well worth the time.