The achievements found in Halo Reach are weird bunch. They're pretty much divided up into four categories; those you get from the Campaign, those you get from cheaping the Firefight mode, those acquired through the menu and those you get playing multiplayer matchmaking. For the campaign achievements, you'll need to be playing in Normal or harder, unless specified otherwise. No playing on easy to get achievements here.
For the achievements that can be gained through the Firefight mode, go to the file browser in Reach and search for the gametype file called “GRCHEEVOS” from user The Juda. That’s me! Use this setup to make getting the Firefight Achievements a breeze. For the matchmaking ones, there’s no easy way around it – you’ll just have to slug it out and eventually get them through hard work, determination and you know, having fun.
Completed every mission in Halo: Reach alone, on Legendary.
When you combine this cheevo with the”God’s must be strong” cheevo, it sure does give you an incentive to complete the game on Legendary all alone. No co-op is allowed through any part of the game for this achievement.
Used the File Browser to upload a file to your File Share.
After playing a round or some campaign, exit out to the Theatre on the main menu and fire up your recorded gameplay in the temporary files. Take a snapshot of anything you like using the camera icon on the menu and then exit out. Go to the File Browser and load up Local Files to see your file. Hit X for the file options and choose Upload to File Share. When you do, you’ll get the achievement.
Killed 10 enemies in a Firefight or Campaign session with the DMR.
Again a rather easy weapon related achievement. Equip DMR rifle, the one that lets you zoom in and pop enemies at a medium distance – pull trigger, hit enemy. Repeat 9 more times without dying. Using the GRCHEEVOS game type and using the NINJA load out, you will net you this reward in about 4 seconds in a Firefight Match.
Reach the rank of Captain in the UNSC.
Reaching Captain isn’t as bad as reaching Lt. Corporal as you only need 210K credits. ONLY 210K credits. Again, this will take some time and there are no easy short cuts.
Complete all of the Daily Challenges in a given day.
In the Menu, there will be a listing for Challenges. Once you enter here, you can see a list of the daily challenges that are set. They can range from a number a specific objectives, but they must be completed that day. It can be a lot of work for 10 points, so you may want to wait until some of the easier challenges come up.
Killed 10 enemies in Firefight or Campaign with a supercombine explosion.
When you use the Needler or Needle rifle, you can stick a number of the needles onto the enemy so that they will explode. It can be tricky to find enough Needlers in the campaign at one time to pull it off, but using the GRCHEEVOS gametype in firefight, you will need to turn the damage down to 100% so that you can get the combine explosion. If you leave it at 300% they will be dead before the explosion goes off.
Hijacked a Banshee during the Reach Campaign.
There are only certain few times that Banshees appear in the game and get close enough to hijack. The easiest part seems to be during the Tip of the Spear mission at the Rally Point Bravo. There will be two Banshees flying around near the spire. Head up the right side to the pipes there and hop up on them. Shoot the Banshee as it gets close and then get near it as it dives down. Jack away for the Achievement.
Let a teammate spawn on you 5 times in an Invasion Matchmaking game.
During the Invasion gametype, when you die, you have the ability to select your spawn point. It can be a static spot on the map or it can be on a teammate. If a teammate uses you as a respawn point 5 times, then you will get this. Best way to get the achievement is to get closer to the action and stay out of harm’s way and away from enemies so they are able to spawn.
Scored 200,000 points in a Firefight game.
Just like the 2 previous score based achievements, you can use the GRCHEEVOS gametype to keep on going and going like some kind of rabbit or something and reach 200K in points.
Recommended a file to someone.
Go into the File Browser from the start menu and go down to either most recommended or most download. You will have the choice of screens or movies and so forth. Select one and then hit X to bring up the file options. Choose “Recommend to friends” and there’s another achievement down.