Zero Hour
The journey begins!

- After completing the very first level, that works has a tutorial/adaptation to the game controls, you'll watch a cutscene of the story and then get the first achievement.

Worst Case Scenario
The threat amplifies!

- You'll be presented with a selection of 4 levels.
- The order that you choose to complete them is irrelevant. Each level has a boss creature to fight at the end and a development of the story will be shown to you once you complete it.
- After completing all of those, you'll get another cutscene of the story and the second achievement.

All Good Things...
Mission Accomplished!

- You'll then enter the final levels.
- They will appear one at a time as a level selection seen below.
- After completing all of them, and the whole game, you'll get the third and final achievement.

- You can aim at an enemy while standing still, make sure you're pressing the aiming button.
- You don't have to kill every single enemy you see, sometimes there's a way to pass through them without engaging combat.
- Save the best weapon charges (scatter and laser) for the final boss and be patient by using the normal one throughout the level:

Thanks! Hope this guide helped.