Unlockables
Unlock the lost levels.
By getting gold medals it is possible to unlock extra levels. On the Main
level select screen press the X button to enter ''The Lost Levels'' menu.
Get ThisBy Doing This
Ancient Rome-Addressing the Senate9 Golds
Ancient Rome-Caesar's Sanctum12 Golds
Ancient Rome-Praetorian Camp3 Golds
Ancient Rome-The Forum of Trajan7 Golds
Ancient Rome-The Forum Romanum5 Golds
Feudal China-The Gate of Supreme Harmony18 Golds
Feudal China-The Silk Road15 Golds
Legendary Atlantis-The Corridors of Power26 Golds
Legendary Atlantis-The Geothermal Tunnels24 Golds
Legendary Atlantis-The Steam Tower22 Golds
The Gallery31 Golds

Reload fast
When you need to reload your guns start reloading then open NETRISCA then wait then go out then your gun will be reloaded

Serious Sam: Next Encounter (PS2) : hints
Bonus levels

Successfully complete the game with the indicated number of "Gold" ranks to unlock the corresponding bonus level. To access them, press X at the level selection screen to display the "Lost Levels" level selection screen.

Ancient Rome - Praetorian Camp: 3 "Gold" ranks
Ancient Rome - The Forum Romanum: 5 "Gold" ranks
Ancient Rome - The Forum of Trajan: 7 "Gold" ranks
Ancient Rome - Addressing the Senate: 9 "Gold" ranks
Ancient Rome - Caesar's Sanctum: 12 "Gold" ranks
Feudal China - The Silk Road: 15 "Gold" ranks
Feudal China - The Gate of Supreme Harmony: 18 "Gold" ranks
Legendary Atlantis - The Steam Tower: 22 "Gold" ranks
Legendary Atlantis - The Geothermal Tunnels: 24 "Gold" ranks
Legendary Atlantis - The Corridors of Power: 26 "Gold" ranks
The Gallery: 31 "Gold" ranks