Starting outside the mine entrance, you'll have to beat up several punks including a couple of knife wielders. Beat them all and you can then enter the mine. Inside the mine the usual punks appear along with Walther yet again. Destroy the barrels you see to get some useful items.

Near the end of the mine there is a guy with a mace along with a few more of the fat guys. After you beat them, you will arrive in a jungle. Move on and you'll soon brontosaurus footprints, and soon enough you'll see a huge dinosaur leg which will keep stomping down. This foot can hurt enemies so just keep moving around to avoid being stomped and let the stupid enemies get crushed instead.

There is another short section with another dinosaur leg to abuse before you'll enter another swamp section, although this one is very short. The dinosaur in the background can't hurt you either, thankfully, and you'll just have to take on some of the hunter, mutants and fatty enemies.

After you defeat them and exit the swamp, take out the single Ferris and then head right to meet three guys and a box. The boss leaps out of the box and attaches itself to one of the guy's faces...

...and transforms into a hideous mutant. This boss, called Tyrog, will swipe at you and also has another attack where his chest bursts open and several sword like objects appear to try and stab you. As usual, lots of other enemies will constantly run onto the screen to help the boss out.

After you beat down Tyrog enough times and defeat him, the parasite will leap off the first guy and leap onto the face of one of the fatty enemies...

...and the second stage of this fight begins. This orange version of Tyrog no longer has the chest attack but can now spit fireballs at you instead. He can also still swipe at you.

Because his fireball attack is fairly easy to avoid, you shouldn't have much trouble taking out this second form. When you do so, you can attack the parasite before it grabs onto another enemy, but eventually the boss will leap onto the face of someone else and transform again.

The third and final form of Tyrog has all of the attacks the previous one had, along with a new move where he spits blood all around himself, which can hurt you. By now there will be lots of enemies on the screen so try and deal with Tyrog quickly.

Your character's dash attack is usually good for getting the boss at long range as he likes to jump around a lot and has a jumping body splash attack to watch out for. Defeat the third form of Tyrog to destroy the parasite for good.