You in essence are a guy that goes through time, looking for crystals, usually with a side-mission or two to complete along the way. You have a cool disguise for each land, a little device that helps you map things out. Always check your mission objectives in your log!
You start out at a Russian Station. You're a female Russian soldier. Lots of metal and snow. Go in and up on stairs, across wood planks and down in hole to get timed mine. Sniper ammo in another building.
Go in building back at start of planks - security door button. Press to open. Note on advanced if you turn the camera off, this activates the sniper above the dam. Take him out from just below the 2nd building back from him, on the right.
Make sure you use the mines on the 2 file cabinets - one each in 2 different buildings. Open the cabinet and then set the mine to burn the papers. Use the mines on the satellite dish on the roof.
Now black door is open. No power - door won't open inside. The powerless doors are all just elevators, and the power is out so you have to go around the long way on the stairs :) Go in up stairs.
Location of shot on person matters - head shot takes out in one hit. So use them :) Duck under any steam.
Up stairs - another elevator door. Just ignore them all. Go in other area - long corridor with boxes.
Little side doors - in to steam pressure valves. Spin them all down to low pressure. In first room, armor on shelf and 547 ammo.
When all valves are to zero, the steam stops and you can go through. The last area has sniper ammo on shelf - more armor. Now down the back set of stairs. Back out on other side.
In building - alert that time crystal is located. You see shelves with watermelons. These are fun to shoot! There are 2 filing cabinets on the left here to burn up. The last filing cabinet is in a room under the stairs. Crates there have boxes and body armor.
Now in to next stairs - checkpoint. In with power generators. High voltage and backup. door - restricted access.
Go into control room. Button over to side - opens restricted door. Shoot wheels and they spin!
Go in the restricted door - strange alien guy. Kill him. Side room #1 is a prison with red bars - grenades on shelf. Room 2 is locked, room 3 has another guard. You can't jump on the boxes. Move on.
"Investigate the secret digging site. Destroy bio-hazard container." You get the Time Crystal! There's a container health meter on screen now. Blow up with mines. The time portal is by 3rd prison door on easy. On medium, you get a computer disk from the dig area and put it into the control room to restore power. This turns on the elevators, so you can go up to the top of teh dam. You have to eliminate the gunship, and then the time portal appears on top of the dam.