Doomed Canyon is the 20th level in Serious Sam 2.
After reaching the Doomed Canyon, Serious Sam taunts some Kleer Skeletons. He kills them, then starts fighting through the canyon. Eventaully, he reaches a cave entrance that has a huge Kleer Skeleton skull surrounding it. After clearing out all of the enemies near the entrance, he enters it.
After traveling through a tight path while a mini-earthquake happens, Sam enters a large cave with lava flowing in it. At first, things appear to be peaceful, but Bone Snakes start appearing. Sam kills them, then travels through the lava cave. On the other side from where he started, he finds an XM-214-A Minigun and uses it to clear out the last bits of resistance in the cave. He then travels through a tight hall that leads to the Boneyard.
1. In the first area, follow the right wall from where you start the level until you see a crevice with a rock pile in the middle. Go behind the rock pile and towards the wall across it, and you'll see a Super Health. Walk towards it, and a secret will register. However, if you pick up the Super Health, several Bull Soldiers will spawn nearby.
2. At the end of the first section, get close to the large skull, then look right. You'll see a hidden path on the wall. Follow it and you'll find a cache that has two Rocket pickups, an Extra Large Armor and a Treasure Chest.
3. Go back to the large skull and face it. When that's done, start walking to the left, and eventually you'll see a raised area with what appears to be a vent on it. There is a nearby rock that you can jump on that'll let you reach the area with the vent. Jump on the vent and then get on the platform it leads to. Follow the platform until you reach the very back of it. When you do so, you'll find a Serious Bomb. Pick it up to register the secret.
4. Right before you pick up the XM-214-A Minigun and Bullets for it, you'll be in a spot where there is a RB-45 Hand Grenade pickup. As soon as you grab the Hand Grenades, look right. You'll see a switch on the right part of the wall. Use the switch, and you'll open up the Secret Word Jumper. Jump across the platforms so that it spells out “SERIOUS”, and you can grab the Extra Life on the other side. If you don't, you will die after a scary sound is played. You do not need to spell out "SERIOUS" when leaving the secret area after picking up the Extra Life. Note that you all you need to do to register the secret is to use the switch.