Outstanding Execution is an achievement that requires you (and minimum one other player) to complete an entire campaign without a single death on Normal or harder difficulty.
- Take your time; this achievement is not timed.
- Bring two Medics to melt the achievement into a cake walk. Save one medi-gun for parasite infestation, and use the other for general healing.
- It is recommended to do this on Normal, since it is the easiest difficulty that unlocks the achievement.
- Make sure the group move as one. Designate front guard, rear guard, and move as slowly as the slowest person in the group.
- This achievement does not require all 4 marines to be present throughout the campaign. It also does not matter if a player joins later as the game is in progress - as long as he doesn't die, the others will still get the achievement.
- Missions can be restarted as long as no marines have died, but if anybody dies, ever, the whole campaign must be restarted.