I wished that I could've played my old save file in which I beat the game, but I couldn't access my memory card.
I didn't even touch main mission. As soon as I gained control of CJ, I used several cheats, one to get me body armor, one to give me weapons, and one to make everyone riot like they do near the end of the game. I occasionally saw buildings in smoke, people carrying TVs, and cars spontaneously exploding. Normally, when this happens, the riot was mostly restricted around the area where CJ's house is: East Lost Santos. But in this situation, the riot was everywhere in the game.
I set a goal for myself: I would get cause enough mayhem to get a 4 star wanted level, and then I would try to go to the airport*, steal a plane and go to another city. It was real challenging. I found myself using the health cheat frequently, although I would eventually die. When I respawned after dying, I used the Body armor and weapons cheat, and got a 4 star wanted level.
When I did make it to the airport, I had to search around for an airplane while evading the police who was hot on my tail.
When I got into an airplane, the police are still shooting at me, sometimes making the plane catch on fire before I could even get off the ground, forcing me to get out and search for a new one.
When I did get it off the ground, I would try to fly it to San Fierro. I usually don't get very far because a Hyrda would come soon and shoot me down. I try to evade it's missiles but to no avail. I remember once when I got into a passenger jet and the Hyrda fired a missile at me almost immediately after I got into the plane! I hadn't even left the ground!
I attempted this a few times before giving up.
(Normally, you can't get into an airport until later in the game, where you get a pilot license, but there's a trick I used. You can climb over the wall near the entrance of the airport if you get on top of a car)
Rating (out of 5):