With this save, your playthrough will turn into an Easy Challenge.
In short: This is a save in which all additional tasks at the beginning of the game have been completed - Ambulance, fire, police, pimp missions, and the burglar tasks have also been completed. Also, races were completed at stadiums: 8-track, Blood Ring, Dirt Track, Kickstar and the Chilliada Cup was completed.
All the collectibles have been collected, all the houses in Los Santos have been purchased, and Karl’s weapon skills and driving skills have been upgraded to the maximum (well, maybe almost).