How do you beat Security Hall level five on Sonic Adventure 2?
On most level five missions featuring Knuckles or Rouge you
should notice that the things you are trying to locate never change
position, so if you are having difficulty in similar situations
just try to remember where they are so that next time you try to
complete you will take less time.
Also, the time limit has been removed which makes this mission considerably easier.
For this level you'll need the Treasure Scope upgrade for Rouge, you can find this upgrade by using mystic melody on a box slightly to the right of the starting position (it's on the second/third floor) and then use the platforms to access the upgrade.
I will list the emeralds' locations in the order of the way you would be able to find using the radar, but you can use any order you wish.
1). From the starting position go to the right into the fans, you should see the red emerald in the far corner. It's a little low for you to reach in your current position, so make your way toward it and land on the nearest platform/metal land and then jump into the fan and try to drill down to get it.
2). Go to the top floor (where you can unlock the safes) and go into the yellow zone, you should be able to see the emerald above the lasers, jump from the junk boxes and glide to reach it.
3). To access this emerald you will need to unlock all red safes (which can be deactivated in the section you found the previous emerald). Go to the lower floor and climb to the ceiling, you should be able to go onto a horizontal support (the highest one in the main level), the one you are looking for has a metal box on it and an enemy. Remove the enemy (it's not necessary, but it may distract you), and then destroy the metal box. Use the treasure scope to reveal a spring. Use that spring to be launched into a switch on the ceiling, which will deactivate a weight on the floor. Go to the weight dig into the safe behind it and get the last emerald (I've forgotten the exact location of the safe, but it's on the floor behind a weight).