So if you do end up playing this, my greatest bit of advice to you would be: always make multiple saves, especially for equipment loadouts.
You can have one save file that's purely for gameplay, trying to go for more of a "purist" run, but then you can also have a save that's entirely devoted to modifying your character. The reason you want multiple saves is that your equipment unlocks can carry over into other save files... so if you play the game as intended and clear the tenth level and save, then load into an alternate save file, all your unlocks and customization options will be the same as in your other play file, even if you've never actually played a level with your body-modding save file. The only things that aren't carried over between save files are body development stats and shards (your currency)... but if you want to see how a particular armor or skinsuit looks without playing the game through multiple times, it's a valid option to consider.
It also helps, in my own particularly idiotic case, if you accidentally overwrite the game file that had over 4000 shards to unlock new weapons, such that you can restore it and not have to worry about grinding shards all over again.