I cannot claim ownership or discovery of this glitch, as I have seen it listed on many other sites. However, I couldn’t find a similar description here, so I thought I would share it with anyone trying to get this Platinum. It helped massively on my Insane run.
Completing the campaign on Medium or higher unlocks the Invincibility cheat. When turning this on at the main menu, it states that egos boosts and trophies will be disabled. However, this only happens if a level ends with the cheat turned on. This glitch is particularly useful for Boss levels (Queen Bitch, Generator Room, Dam Top, and Final Battle). It also helped with the Crash Course level, and that horrendous turret section.
Below is a step by step guide to make this glitch work. I will use “Crash Course” as an example.
I couldn’t make this glitch work for 2 or 3 part levels. Additionally, some levels like Dam Top do not have a checkpoint after the boss battle. The trick here is edge forward until the screen begins to fade to black. Immediately pause the game and wait until the ‘saving’ icon appears. Now exit the game, check the level on chapter select, and it should have worked. It did for me anyway.
- At the chapter select screen, select ‘Crash Course’ and the ‘Insane’ difficulty.
- Play through the level as normal, until you reach the turret section. You will notice on the bottom right of the screen that a ‘saving’ icon will appear. Wait for this to finish and exit to the main menu.
- In the extra game settings, turn on ‘Invincibility’, and ignore the warning icon.
- Resume the game, which will return to the beginning of turret section with invincibility turned on.
- Beat this section. After the gunship falls, and you climb over the previously blocked barrier, another ‘saving’ icon will appear. Wait for this to finish and exit the game.
- Simply reload the checkpoint again. No need to turn the cheat off as it disables automatically.
- Resume game and finish up the level. If you now look on the chapter select screen for ‘Crash Course’ the ‘Insane’ difficulty icon should now be highlighted.
I believe the cheats ‘Infinite Ammo’ and ‘Instagib’ also work using this method, although I did not test this out.
Hope this helps, if anyone needs level specific advice please give me a shout.