Such a rad shot. Great use of the colour palette! How the heck did you do this with 192 GB tiles??? Or is the 'crushed' version simplifying it to fit?
I actually used 131 tiles! The aseprite tilemap feature was super useful to make sure I didn't go over the maximum but in the end I even had a little extra room :)
And the answer to "how" is a few happy coincidences and a lot of repeating tiles. The most unique tiles are kept to only a few and everything else is simple tiles reused to create the landscape!