The 1GB is compressed due to Itch limits. The uncompressed game is already 5.5 Gb. If you want the full resolution you have to use the Launcher or download from Mega/Mediafire
does the uncompressed game have a story side and more missoins? or it's just better in graphics and game scane only? i play this game in Android. to download tha game i have to have a 4x size of the game to install it!! that's what i found in my period of playing the game! and 5.5GB mean i should have 5.5x4= 22GB free size in my mobile!! that is not easy you know what i mean? 😅