Anyone completed this on the insane difficulty level yet? If so, is it actually that hard?
Got up to Level 6 boss then quit for now as its really tough. You get the same save points & ammo as before but use a lot more ammo as everthing takes more hits and you lose most of your health in 1 hit so need to buy lots of health packs. You can use the following cheats once only per save game to make it easier once you have entered these cheats and save the game it remembers so the only way to reuse them is to start new game:
Except for these 2 cheats below work all the time:
Press Start then XXYYY - Refill Oxygen
Press Start then XYYXY - Refill Stasis
These cheats below only work once per savegame:
If you entered the code correctly, you will hear a sound. Press Start or B to resume the game with the code(s) activated but you have to pause/unpause for each cheat.
+2 Nodes
Pause the game and press: Y, XXX, Y
+ 5 Nodes
Pause the game and press :Y, X, Y, XX, Y, XX, Y, XX, Y
+1,000 credits
Pause the game and press: XXX, Y, X
+2,000 credits
Pause the game and press: XXX, YY
+5,000 credits
Pause the game and press: XXX, Y, X, Y
+10,000 credits
Pause the game and press: X, YYY, XX, Y
All Cheats Do not affect achievements at all but even with them & that Military suit glitch impossible mode is still very challenging

Best way to tackle it is to do the following:
1: Buy the DLC for better suit+weapons.
2: Or Complete the game on easy restart a new game on easy again without saving then after getting the Level 6 suit which is available from your just completed game play the game through again on easy mode as usual without entering any cheats.
3: After completing the game for the 2nd time on easy start another new game straight away this time on Impossible mode and now enter all the cheats and save the game so you will have a good headtstart with a better suit+plenty of credits/nodes.
Remember do not save the game straight after completing it on easy twice
only after you have started an Impossible mode WITH the suit you finished Easy on otherwise you will be back to square one!! Will still be hard in places but its now doable!!