Metal Slug 3

Complete mission 2 without losing a single life. This can be done in single player or co-op.

This levels not too bad as the zombies are obviously very slow but strong, they take quiet a few bullets to go down. The 'rotten fluid' that they spit at you will turn you into a zombie, making your character move and jump slower but you gain the ability to fire a special attack which is a thick line of puke so to speak that spreads across the screen pretty much instantly killing any enemies in its path.

At 1.23 in the video you will see the President and two POW's underneathe the main path, to save these guys just hold 'down' to crouch and walk along this path. Free all three guys including the President and if you dont already have this achievement, you will now: As a thanks for saving him, the Presidents bodyguards give you a coin and a Thundercloud powerup that helps you out a little bit to work your way up the small hill. But after wiping out the next set of Zombies despite possibly still having ammo left the for the Cloud, it won't follow you just before you see the soldiers running towards you.

Now you dont have to enter the ice cave halfway through the level (3.55 in the video), its hard to not notice so avoid it if you can. The enemies in the cave can be annoying and require a ton of constant jumping and dodging. Plus once you have reached the end of the cave you have to work your way back out of it, but you do get to ride the huge Elephant Slug!

Carry on to the right after wiping out a few zombies, once you run halfway down the hill throw two of your grenades at the Grey Tank at the bottom of the hill. Be careful if the Tank turns its turret to shoot up the hill as it can sometimes get a shot off just as it dies and can easily not be spotted and catch you out. Very rarely there will be another Tank behind the first so just quickly hit it with two more grenades.

Moving forward wipe out the soldiers and the small compartments they come out of but keep a little bit of distance, each time you blow up the compartments a strong zombie will spawn from each one. The Zombie will attack you with rotten fluid which covers a decent distance in front of it so be careful. After you kill the last Zombie an enemy jet hovers above you dropping slow rockets at you, very easy to dodge and the jet is really easy to kill. Once you finish the jet off it will drop a Rocket Launcher, pick this up and move forward and then you can follow the video again at 4.50.

The boss is not too hard, to start with there will be a bunch of aliens (monoeyes) that circle around you firing at you in slow and steady patterns. Leave yourself enough space to run to either side of the screen to dodge the projectiles while constantly shooting and throwing your grenades.

After you have killed the aliens an egg type thing (The Ten Commandments of Moses) spawns from the ground, just continue to shoot away at it while dodging the headstones (Monoliths) that try to land on you. Pretty simple, here are a couple of videos to help out if you are struggling. Good luck.

(Credit to TK2008BEST for the (first two) amazing videos)