On Certian missions in the past ( NOT preperation) If you fail you get a different ending where you appear in an interrogation room (the same one as in the first level, isolation) and a mysterious voice talks to you and somehow helps you.
P.S. i have only got up to the level past reliance so i only so far got them on reliance and feild work)
Field work: shoot a member of winter ice team and kill them.
Reliance: Get seen by a guard in the first building and get a fire fight started, DONT help the commander, let him die!!
On the reliance level, when you first enter the first building, on the ground floor go the the far left door and tranq the two guards, then play the arcade. When you complete the level you can play it at any time you want through out the main game by pausing and selcting appliacations and selceting the earth impact game.
First you need to be in the Madness level. Before the third checkpoint you need to find a room with a guard protecting the door and go through. Once in, look on top of the shelf for a disc. Use the Telekinesis power to obtain it and insert it in any computer you can find on the level. This disc will unlock the X-Space '92 Mini Game.
At the beginning of the level where you obtain the Psy Attack ability, you'll find a computer by a dead guardd. Go into the computer and use the program represented by a smiley face icon. Click it and you will go into a chat room with the dead guard's girlfriend!