Resident Evil Revelations

To earn this achievement, I HIGHLY advise you to first do a playthrough in Easy or Normal (probably doing the no deaths run at the same time). Then, you'll be able to jump in New Game+ in Infernal, which lets you keep all your weapons and parts from the first playthrough.

As a general tip on Infernal, try to avoid any enemy you can, saving ammo and health that way. There will be additional and stronger enemies even on the early levels, and they will take a lot of shots to kill. There are also special gun parts for this mode, which will help you tremendously to progress. You can find the list here: https://www.evilresource.com/resident-evil-revelations/weapo...

I used the PSG-1 rifle, Hydra Shotgun and P-90 machine gun for most of the game, and the Magnum for the last boss. Some sequences are harder than others, mostly the ones where you control other characters, but if you use the Legendary parts, avoid the enemies you can avoid and search every room with the Scanner, you should be able to progress through the game without too many problems.