There are 28 Ego Awards. There are a few extra rewards that are gained automatically by playing through the story. If you get all Ego Awards during your first playthrough, you will unlock the "I Am All That Is Man" achievement in the "Blowin' The Dam" chapter.
You can find poop in toilets. There is some poop in the toilets in the room where the game begins, in the "Duke Lives" chapter. Grab some poop from a toilet and throw it to earn the "Turd Burglar" achievement.
After loading up the Chapter called "Duke Nukem's Titty City", go behind the Bar on that level to find a closed Door that requires a code to be opened. The Code is: 4768. Inside you'll find a beer, which is part of the "Party Animal" achievement and a porn film starring the Dukester himself.
In the level "Duke Nukem's Titty Club," go through the Restrooms halfway and on the left side take a door with an "EXIT" sign over it. Head upstairs until you reach a small room. At the end of it a desk with a surveillance monitor on it and, next to it, the "Totem" from the movie "Inception" spinning without stopping.
Pinball games are located in various locations throughout the game. The first pinball game is found in "The Duke Cave" chapter. To speed things up while playing the pinball game, get at least a x2 multiplier without wasting a ball. Hold the top left flipper and bring the ball up there. Then, immediately release the flipper and let it hit the three panels. If the ball is getting too far on the right side, you can tilt the table to the left. Repeat this method without using the tilt ability more than once every five seconds. If you use it too often, you will lose control over the flippers.
A great opportunity to kill three aliens at once is early on when you must destroy the large ship with the laser gun on top of dukes building. After firing on the ship twice, two alien carriers will take position in front of you. Immediately fire at the ship (not the aliens) and they will all blow up with the ship.
In the "Duke Nukem's Titty City" chapter, drink all nine beers in the strip club to unlock the "Party Animal" achievement. One beer is behind the locked door; the code is "4768". Get all the other items required to continue the chapter. After giving the items to the stripper, you can enter the last room.
To defeat the energy leech, keep the freeze ray on you from the previous level. As soon as the fight scene with the leech starts, it will slam its body on the sea bed. When this happens, zap the leech with the freeze ray and the leech's energy will be reduced down to the red, so you will only need 1 hit with the RPG to finish this beast off.
Complete the game under Normal difficulty or higher to unlock the following cheat options at the "Extras" menu:
Concept Arts Development Timeline Duke 3D Freeze Ray (freeze ray fires bouncing ice projectiles) Duke Sound Board Game Speed (adjust game speed) Grayscale Mode (black and white graphics) Head Scale (adjust head size of enemies and NPCs) - Easy difficulty or higher. Infinite Ammo (cheat; self-explanatory) Instagib (cheat; enemies killed with one shot and always gib) Invincibility (cheat; no damage from bullets or explosions) Mirror Mode (graphics are mirrored horizontally) Movies Screenshots Triptych Office Photos
In Part 2 of "The Forkstop" chapter, you will come across a large area where you must turn the power on. After killing a few waves of enemies, use the forklift and climb the wall to your right. Grab the heart barrel, and go to the other side. Place the barrel on the blue heart drawing on the ground to open the secret room and unlock the "Companion Barrel" achievement.
In "The Shrunk Machine" chapter, near the start and after entering the first large room, straight ahead across the room are some double doors. Look at all pages on the calendar on the wall behind the double doors to unlock the "I Need A Date" achievement. There is another calendar in Part 2 of "The Forkstop" chapter on the wall in one of the rooms.
In the "Damn It’s Late" mission, you will see an actor yelling at someone once you walk off the set. He says things like "You're a nice guy, you really are but you're a fucking amateur" and "Do you want me to trash you're mics? DO YOU?".This is a reference to when Christian Bale yelled at a crew member on the set of Terminator Salvation.
At the start of "The Duke Dome" chapter, you will get an infinite amount of explosives when entering a building. Throw a trip mine directly on one of the enemies to earn the "Sticky Bomb Like You!" achievement.
At the start of Vegas in Ruins, the 'power armor' in the armor crate at the beginning of the level is none other than that of a Spartan -- and Master Chief's classic green and orange color scheme, no less.
In the "Duke Nukem's Titty City" chapter, play a game of air hockey in the game room at the back of the club. However, rather than focusing on scoring, try defending your goal as best you can. The rest will happen by accident since the opponent is very weak.
In the "Titty City" chapter, there are two ATM machines; one near the bar and one near the slot machines in the game room. Go up to one and use it. It will say "card read error". Press action again and it will say "Feed me a stray cat" --a reference to the scene in American Psycho where Patrick Bateman tries using an ATM machine and it appears to him to say "Feed me a stray cat".
ACHIEVEMENT - HOW TO UNLOCK Extermination (25 points) - Kill 50 aliens. Annihilation (40 points) - Kill 100 aliens. Nuclear Devastation (50 points) - Kill 250 aliens. Hippy-Stomper (20 points) - Foot stomp 12 aliens. Judge, Jury, Executioner (20 points) - Execute 20 aliens. Trapper (20 points) - Kill 10 aliens with Trip Mines. Freeze Well! (20 points) - Kill 15 frozen aliens. Road Rage (20 points) - Kill 15 aliens with the monster truck. Fork the Pork (10 points) - Kill 6 aliens with the forklift. Dead Useful (15 points) - Kill 10 aliens with environmental explosives. Downtown Barrel Beatdown (15 points) - Kill 10 aliens with tossed objects. Duke Angry, Duke Smash! (20 points) - Kill 15 aliens with melee attacks while on steroids. Noms (10 points) - Eat 10 pieces of food during the SP campaign. On the Noggin (25 points) - Kill 30 aliens with headshots. Natural Disaster 3x (10 points) - Kill 3 aliens at once. FBT (10 points) - Get knocked down 10 times. Turd Burglar (10 points) - Find and steal a piece of poo. I Need a Towel (10 points) - Get hit by 10 Pregnator bombs. Baron von Nukem (20 points) - Shoot down 20 alien fighters. I Need a Date (5 points) - Look at every page of a calendar in SP. Sticky Bomb Like You! (10 points) - Put a Trip Mine on a live alien. Big Guns, Big Ships (10 points) - Blow up 5 enemy gunships or dropships. Air-Duke (30 points) - Win air hockey with a score of 7-0 in the strip club. Balls of Steel (25 points) - Earn a 1,000,000 pinball score in SP. Flagon of Chuckles (5 points) - Drink a beer in SP. Juiced (5 points) - Take steroids in SP. He's Got a Hologram! (5 points) - Use a Holoduke in SP. Drawrings (10 points) - Doodle something on the whiteboard in SP. Substance Abuser (10 points) - Drink beer while on steroids or vice versa in SP. I Am All That Is Man (40 points) - Discover all Ego cap awards. Gunslinger (50 points) - Carry the gold pistol through the whole SP campaign. Piece of Cake (20 points) - Complete the SP campaign on Easy Difficulty. Let's Rock (30 points) - Complete the SP campaign on Normal Difficulty. Come Get Some (40 points) - Complete the SP campaign on Hard Difficulty. Damn, I'm Good (50 points) - Complete the SP campaign on Insane Difficulty. Special Thanks (5 points) - Watch the credits all the way through. Bucket Head (30 points) - Find all 3 helmets in the SP campaign. Call Waiting (25 points) - Listen to all phone messages. Party Animal (10 points) - Drink all of the beers in the strip club. Pescaphobe (10 points) - Kill all the catfish in the underwater level. Sunday, Black Sunday (5 points) - Shoot down the blimp above the stadium. Nobody Likes a Whiner (5 points) - Knock out the talent at the talk show. Lots of Whacking (25 points) - Win a game of Alien Abortion in the strip club. Companion Barrel (10 points) - Unlock the secret closet at the end of the Forkstop. One-Eyed Freak (10 points) - Defeat the Cycloid. Pit Champion (25 points) - Defeat the Battlelord in Las Vegas. Not Bad for a Human (40 points) - Defeat the Alien Queen. A Good Dam Fight (25 points) - Defeat the Battlelord on the Hoover Dam. Octacide (25 points) - Defeat the Octaking. Beating the One-Eyed Worm (35 points) - Defeat the Energy Leech.
"The Doctor Who Cloned Me" achievements ACHIEVEMENT - HOW TO UNLOCK Bubble Buster (10 points) - Kill 10 expanded enemies with melee attacks. Threesome (10 points) - Kill 3 enemies within 3 seconds with the Impregnader. Bloody Red Rover (10 points) - Kill 30 enemies with the moon rover. Scientits (10 points) - Earn a 1,000,000 pinball score on the Scientits pinball machine. Heart to Heart (20 points) - Finish Doctor Proton. Another Piece of Cake (20 points) - Beat The Doctor Who Cloned Me campaign on Easy Difficulty. Let's Rock Out (30 points) - Beat The Doctor Who Cloned Me campaign on Normal Difficulty. Come Get A Little More (35 points) - Beat The Doctor Who Cloned Me campaign on Hard Difficulty. Damn, I'm REALLY Good (40 points) - Beat The Doctor Who Cloned Me campaign on Insane Difficulty. I Am All That Is Man - Again! (20 points) - Discover all Ego cap rewards in The Doctor Who Cloned Me campaign.
In "The Hive," after opening a couple alien doors, you will encounter a room with tons of spore-looking things near the doorway. Take a left, then turn on your Duke Vision and crouch, under the branch like things. Then, at the end of the cave you ducked through, there is a dead EDF marine. Walk up to him to have Duke say "That's one dead space marine." His helmet looks a lot like Isaac Clark's helmet from Dead Space.
The first helmet is at the very start of the "Vegas In Ruin" chapter, in the back of a vehicle. The second helmet is at the start of "The Hive" chapter; turn left after going through the first alien hole to find it. The third helmet is located in the "Blowin' The Dam" chapter; after planting the first bomb and fighting two octopuses, swim to some debris to your left to find it and unlock the "Bucket Head" achievement.