PC save files are located at:
<Steam-folder>\userdata\<user-id>\287700\local\
<Steam-folder>\userdata\<user-id>\311340\remote\
TPP uses GZ directory (311340) to store actual save files and backs them up in TPP directory (287700) for Steam Cloud sync.
Save file names:
PERSONAL_DATA<index>
TPP_CONFIG_DATA<index>
TPP_GAME_DATA<index>
TPP_GAME_DATA<index>
Save file name is set in lua, 00_dat/Assets/tpp/script/lib/TppDefine.lua
. You can change it to keep main save file safe.
Save files are encrypted with symmetric algorithm. Their contents are player-specific variables (like GMP, staff etc.) and lua variables encoded in strcode32.
Use TNT to decode/encode files and inspect their contents.