Frostpost is the 33rd level in Serious Sam 2.
After a bit of fighting, Sam reaches the Laser Cannon's compound, but it is guarded by many enemies. Sam clears them out, then blows open the door to the Laser Cannon, ready to use it against Sirius' shield.
1. Right before you enter the first room with heating in it (not a hangar), look right. You'll see a shipping container with “TOP SECRET” on it. Blow it up with the XPML30 Rocket Launcher to reveal a RAPTOR Sniper Rifle, Large Health, Serious Bomb and a Backpack. Blowing the container up will register the secret.
3. Go past the pipes that Santa was on, turn right and walk until you see a hangar on your right. Go inside it, then look again to your right. You'll find another shipping container with “TOP SECRET” on it Blow it up with a Rocket to reveal several ninja chickens, which will register a secret. Killing each rabbit will reveal either a Extra Small Health or a Extra Small Armor.
4. Past the second heating room (across the pipes where Santa was) is a shipping container that will burst open with Orc Grunts when you get close to it. Go behind the container to find a Serious Bomb. Pick it up to register the secret.
5. Before entering the third heating room (the one past the large walkway) you'll see three shipping containers on your right. Shoot a rocket at the right-most one to blow it open and register a secret. Inside it is a Serious Damage.