Tip for those starting this game:
I just wanted to highlight something that I felt helped me out a lot when I played through this game. When you start the game you will be in a big courtyard. My suggestion is to run around this area, as well as opening the door at the top of the steps to your left (when you spawn) and grabbing all of the keys.
After that, play one of the missions. When you return to the courtyard, the keys will be back. Run around and collect them again. Then you can really start to grind. Just run in to a completed mission, press start and hit
to quit the mission. Every time you do this, collect the keys. Do this until you have about 100. This way, whenever you run into chests throughout the game, you can always open them. There is nothing worse than getting to the collectible and not being able to grab it, requiring you to replay some pretty bland missions. I found 100 keys lasted the whole game, supplemented by any I found from that point onward. Though plenty later on, there are points where you go through keys quickly before being able to restock. Only takes about 15 minutes, and can save a lot of time later on.
Arcade games 100%
Retail games 100%
1,000th Achievement: A Monument to All your Sins (Halo: Reach)
10,000 Earned: Jan 2, 2010
20,000 Earned: June 28, 2010
30,000 Earned: May 30, 2011
40,000 Earned: March 17, 2012
50,000 Earned: June 10, 2012