Halo 2

These achievements stack, so do the game on Legendary first to save yourself doing the game more than once. It can and will be frustrating at times, but perseverence is key. If you are stuck at any point, use this guide for help. It is an amazing walkthrough with videos and it gives tips on parts where you can skip entire battles, which is extremely nice.

General Tips:

• The plasma pistol/battle rifle (aka noob combo) is the best thing in the game. Hit them with a plasma blast, then switch to the BR and headshot, this will kill most enemies in one go.
• Your shields recharge, make use of it. Get out of battle if you've been shot, more will follow soon after.
• Use your NPCs. Let them go into battle first to draw fire, then you can attack while the enemies are focused on them. Also, giving them a good weapon will help, since they won't run out of ammo. If you have a rocket and there are a lot of vehicles attacking you, giving it to the NPC and letting them fire rocket after rocket will help.

• Grenades are clutch. Make sure you make every grenade count, since you can't carry many, but they will do a great deal of damage. If you have stickies, make sure you get them to stick or the enemies will most likely get out of the way.