Giant AlienAs the cut scene indicated you are in trouble. The giant egg opens and releases a giant alien creature. Use your best weapon. So take the Uzi or the Shotgun. You have to stay on the edge of the platform, but don't get to close or you might fall over. Don't let the alien get to close. It will crush you with its claws. It's best to sprint into a corner. Make a roll and fire at the alien. Run into the next corner and repeat the procedure. If you run from corner to corner in a circle you might have the best chance. For some reason, I found counter clockwise the easiest.
Movable Crates and Fast Closing DoorsAfter the Alien is gone collect the Uzi ammo in the corners. Follow the passage. At the end slide down. On your right is a crate. Leave it alone. Run further down. Push the crate there three times. Run up to the right. Push the crate there once. Climb onto that crate. Turn around and jump up to the next platform. Pull up and save your game at the crystal. Quickly run through the snapping doors. Careful the last floor tile in front collapses. This is how you get through: Position in front of the collapsing tile. Wait till the door starts closing. Then run through quickly when it opens again.
LavaTurn right. Push the crate at the end once. Run back up and then down the other passage. Climb over the block and push it twice. Take the other passage back up and get onto the crate. Use the lever. Step through the door that opens behind you. Step outside. Make a standing jump onto the darker platform on your right. Make another standing jump onto the next platform. Then aim for the platform on the other side of the lava. Now take a running jump onto the next platform on the other side.
Turn around. You can now see a bridge lowered at the other end of the room. Return there and enter the passage on the right. Pick up the magnum ammo, the shotgun shells and the large medipack. By now the bridge has dropped again. Use the lever in the corner. If you use it twice the bridge will stay up forever. Get back out. Again jump over to the last platform on the right.
BouldersStep into the next passage. Turn around and jump backwards up - so you won't have to turn around again - the slope till the boulder comes down. Quickly run out. Then enter the passage again. Run up to the top. Turn right and right again. On your left it an alcove, guess what that means. Look up to the right, there is another boulder. Trigger it like the one before. You have to get at least above the grey spot. Run up after the boulder is gone. Turn left again. Turn right.
Jumping and SlidingThere is a collapsing tile. Trigger it but get off quickly. Fill up your energy. Then hang from the ledge and let go. Run towards the scion again. Get your guns out and shoot at it till it explodes. Save your game at the crystal. Enter the passage and run over the drawbridge from before. Run down the slope. Kill the three creatures jumping around in the passage. Then drop onto the grey rocks lying around in the lava trench. In-between is an opening where you can drop onto a platform below. Turn to face the red wall. Take a running jump there and grab the ledge. Shimmy right. Drop onto the platform at the end and make a backflip to land on a safe square. Step into the passage. Walk down the slope on the right side. A boulder rolls down the left. Now go over to the left. Jump past the blade onto the safe spot in the spikes. Walk through the spikes to the next pit and jump over it. Turn left and go up the ramp. Face towards the opening. Jump forward. You will land on the bridge. Hold down the jump button and press forward to continue from the bridge into the opening.
In the next chamber go towards the left wall. Jump over to the orange part and grab the ledge. Shimmy right. At the end let go. Collect the Uzi ammo and the two large medipacks.
Boulders and BladesJump towards the gap in front. Hold on and shimmy right. Drop onto the first safe platform. Now you have to run over the collapsing floor and into the passage with the blade on the right before the boulder can hit you. Start when the blade swings to the left. Instead you can also wait on the last collapsing tile and grab the ledge. Wait there till the boulder went past overhead. Now run down the hill on the right. The next boulder will come down behind you. Run into the passage on the right. Turn around and jump over to boulder to get the small medipack. Jump back. Slide down the next hill. Careful there is a blade. Jump at the end to get out of the way. Follow the passage. Lava will come from both sides. Stop at the small medipack and pick it up. Then continue along the passage to the other side. I recommend jumping over the second lava stream. Pull the lever and step through the gate. Turn right. Pick up the Uzi ammo. Turn around and run towards the pit with lava. A boulder will pass overhead. Make a standing jump forward and grab the ledge to avoid a second boulder. Pull up and follow the path.
Fire and WaterStep out to the right. You will come to a room filled with water. There are pillars with fire on them. Approach the first pillar with fire. Jump onto it staying close to the side. Run along and jump onto the longer platform. Get past the fire there and jump onto the next column. Continue onto the platform at the other end. Step out into the next chamber. Walk forward. Make a standing jump towards the platform where the blade is. Grab the ledge and pull up. It will give way. If you don't want the secret just drop down.
Quickly make a running jump into the opening ahead. Pick up the large medipack. Walk back into the doorway make one step back, then make a standing jump forward.