Each level has 3 secrets, and finding them all in all 4 levels, enables you to access the Bonus Level: Nightmare in Vegas. Below, you can find the basic info about each level-size, secrets and other stuff such as enemies, items and puzzles
1.Cold War
2. Fool's Gold
3.Furnace of the Gods
4.Kingdom
5.Nightmare in Vegas
1.Cold War:This level is not very big, in fact, it is medium sized. You can use a snowmobile there. The hardest secret to find is the golden skull. There is not really much to say about this level. You just explore a Russian base, kill some guards, crows and snow leopards and collect some keys. Then you harpoon some sharks, use a zip line and you've made it to the second level.
2.Fool's Gold:This level is quite big. You can use a snowmobile there and kick some baddies' asses. The secrets are quite hard to find as well.
3.Furnace of the Gods:This level is huge. You will meet some helpful natives but, also, some goons, white bears and yellow fish which won't be quite as friendly as the first ones. There are some boulder and spike traps and you have to solve a lever puzzle to flood a room. The special thing in this level is the beautiful waterfalls of melting gold. Don't jump into it, though, because you'll get a nasty surprise.
4.Kingdom:This level is not very big ,but finding all three secrets requires you to be cautious and be good at making accurate combo jumps. You have to solve a rather hard lever puzzle and fight with some ugly brown monsters that remind me of the Yetis in Tomb Raider 2.The boss enemy is a creature that looks like the Guardian of the Talion and you have to trap it in order to defeat it.
5.Nightmare in Vegas:This level is a great reward for finding all twelve secrets. It takes place in a hotel in Las Vegas. The textures and the objects are just awesome. You can even find Winston, a stage, some nasty baddies and a creature that looks like the one you met in the previous level (Kingdom). Maybe it is his twin brother and wants to take revenge!