This achievement was the hardest for me, u can t buy anything in the ship and player upgrades, basically complete the game without spending experience and gold. No extra life, no sprint, no extra stamina and only 1 crew member and item slot. That means if u save 1 crew member with revive ability and 1 medkit for the final boss u need to do it with max 3 full health bar (base one, one full bar with revive if u die and another full bar if u use a medkit when low health).
If u practice with the game u should have no problem reaching the final boss but remember to not rush in the last island and kill enemies one at a time cause group enemies are dangerous. Without sprint is really difficult to avoid some boss attacks, that s why u need something to full your health (medkit and crew member) so be sure to save them for the last boss.