1943	Must completely destroy final battleship to beat the last level.
10 Yard Fight	Win the Super Bowl
720*	Finish class 4
Advanced Dungeons & Dragons: Hillsfar	Finish the game with one of the characters
Adventures of Dino Riki	Loops after level 4-4
Air Fortress	Similar to Ghosts 'n Goblins game must be played through twice to reach the credits.
All Pro Basketball	Must play 35 games and beat each team 3 times
Alpha Mission	Loops after area 12 (area 13 is just area 1 again)
Anticipation	Win a game versus the computer
Arch Rivals: A Basket Brawl!	Win a single game
Archon	Win or draw versus the computer (same credits sequence either way).
Arkanoid	Must beat without using continue code. Warp code allowed (mentioned in manual). Probably impossible to beat without a Vaus controller.
Arkista's Ring	Must complete four loops to get to the ending.
Athletic World	Obtain a degree for finishing a round with a good enough score
Balloon Fight	Beat the high score in both 1 player and balloon trip modes
Bandai Golf: Challenge Pebble Beach	Complete 18 holes of golf
Bandit Kings of Ancient China	Finish scenario 4 to get the ending
Barker Bill's Trick Shooting	Play and beat each event, including the special ones in Fun Follies mode (stage 4, 5, 9)
Base Wars - Cyber Stadium Series	Win pennant mode
Baseball	Win a single game
Baseball Simulator 1.000	Play and win a season. The shortest is 5 games.
Baseball Stars	Win a league
Baseball Stars II	Win a league
Bases Loaded	Must win 80 games
Bases Loaded II: Second Season	Must win 75 gamesn the World Series
Bases Loaded III	Beat a level 5 team with a rating of 100.
Bases Loaded IV	Must win 70 gamesn the Super Series
Battle Chess	Win a single game
Bill Elliott's Nascar Challenge	Play and win the Championship Season
Black Bass	Win a Class A tournament and finish the season
Blades of Steel	Win a tournament
Bo Jackson Baseball	Beat the playoffs mode
Bram Stoker's Dracula	Must play on hard difficulty to play the full game.
Break Time: The National Pool Tour	Win the national pool tour
BreakThru	Loops after level 5
Bubble Bobble	Beat the game with the good ending. Not necessary to do second quest.
Burgertime	Loops after stage 6
Caesar's Palace	Must have $140,000 to leave in the best car.
California Games	Set a new world record in each event
Casino Kid	Must win $2 million.
Caveman Games	Compete in the caveman games and set records in each event
Championship Bowling	Complete a game of bowling and beat the high score
Championship Pool	Win either the 8 ball or 9 ball tournament (not necessary to do both)
Chessmaster	Win a single game
Chubby Cherub	Loops after stage 12
City Connection	Loops after stage 6
Classic Concentration	Win a single game and win the bonus round at the end.
Clu Clu Land	Loops after stage 21
Commando	Beat stage 4-4
Conflict	Must beat all 15 maps to reach map 16 to complete that one
Crash 'n the Boys: Street Challenge	Win first place as Southside for the ending
Cyberball	Win a single game
Dance Aerobics	Beat all modes
Defender II	Loops after stage 1
Dig Dug II	Loops after stage 72
Donkey Kong	Loops after stage 3
Donkey Kong 3	Loops after stage 4
Donkey Kong Jr.	Loops after stage 4
Double Dare	Win a game versus the computer
Double Dragon II: The Revenge	Must play on Supreme Master difficulty to finish the entire game
Double Dribble	Win a single game
Dr. Mario	Complete virus level 20
Dragon Spirit: The New Legend	Intro stage must be completed without dying to play as the blue dragon, which allows you to play all stages.
Duck Hunt	Loops after stage 1. So just beat at least one round and the high score for each mode.
Elevator Action	Loops after stage 4
Evert & Lendl Top Player's Tennis	Must win all tournaments to get the ending (add more details) rank 12 after asmik, rank 8 wimbledon
F-15 Strike Eagle	Complete all 7 missions
Family Feud	Must win $20,000
Flying Dragon: The Secret Scroll	Similar to Ghosts 'n Goblins game must be played through twice to reach the credits.
Flying Warriors	Play on expert difficulty to get the true final boss fight
Galaga	Loops after stage 3
Galaxy 5000	Beat Pluto without continuing to get to the final race - Planet X. Win that race to get "The End:"
Gauntlet II	Consider beating stage 100 as finishing it.
Gemfire	Beat scenario 4 to get the ending
Genghis Khan	Choose "World Conquest" and take over the map
Ghosts 'N Goblins	Must be played through twice to reach the credits.
Goal	Win a World Cup
Goal Two	Win a Super Cup
Golf	Beat the default score (+28)
Golf Grand Slam	Get the best score after 18 holes.
Gotcha!	Loops after stage 3
Greg Norman's Golf Power	Play 18 holes of golf
Gyromite	Must beat Game A & B
Harlem Globetrotters	Win a single game
Hatris	Beat level 9-5
High Speed	Beat the high score
Hogan's Alley	Loops after stage 1. So just beat at least one round and the high score for each mode.
Hollywood Squares	Win a game versus the computer
Hoops	Win 15 games
Ice Climber	Beat all 32 stages.
Ice Hockey	Win a single game
Isolated Warrior	Must beat first 6 stages without continuing to reach final stage.
Ivan "Iron Man" Stewart's Super Off-Road	Get to race 36 (race 35 is the eighth and final new race)
Jack Nicklaus' Major Championship Golf	Play 18 holes of golf
James Bond Jr.	Similar to Ghosts 'n Goblins game must be played through twice to reach the credits.
Jeopardy!	Win a single game
Jeopardy! 25th Silver Anniversary Edition	Win a single game
Jeopardy! Jr. Edition	Win a single game
John Elway's Quarterback	Win a single game
Jordan vs. Bird: One-on-One	Beat the computer in each mode
Joust	Finish wave 16
Karate Champ	Loops after round 10
Kick Master	Complete the game once.
Kickle Cubicle	Special stages not necessary
Kings of the Beach	Win a tournament
KlashBall	Win the league
Lee Trevino's Fighting Golf	Win a nassau game vs the computer
Legend of Kage	Ending appears after 3 loops
Legends of the Diamond	Tournament mode
Lemmings	Start on hardest difficulty to reach the credits quicker (you're only required to do the final 25 stages)
L'Empereur	Beat scenario 4 to get the ending
Little League Baseball: Championship Series	Win a championship series
Lode Runner	Complete all 50 stages
LoopZ	Get a high score on Games A & B, and clear Game C
Lunar Pool	Beat the game on a single credit to get the ending screen
M.U.L.E.	Beat the computer opponents on normal.
M.U.S.C.L.E.	Loops after stage 4
Mach Rider	Loops after stage 10
Magic Darts	Complete each game of darts
Magic Johnson's Fast Break	Win a single game
Magician	Complete the game once.
Magmax	Loops after second boss; there's a brief transition period and then you return to stage 1
Major League Baseball	Win a single game
Mario Bros.	Loops after phase 18
Mighty Bomb Jack	Any ending is fine.
Millipede	Loops after round 16
Monopoly	Beat a computer opponent in a single game
Monster Truck Rally	Finish monster truck rally mode with the highest total score, vs at least 1 cpu opponent
Ms. Pac Man	Loops after stage 13
NES Open Tournament Golf	Win $1 million
NES Play Action Football	Win the playoffs mode
NFL Football	Win a single Super Bowl game
Ninja Kid	Loops after stage 8
Nobunaga's Ambition II	Choose the scenario "Nobunaga's Ambition" and take all territories
Operation Wolf	Loops after you've completed all 6 missions
Othello	Beat level 4 to unlock level 5. Then beat that.
Overlord	Play on the hardest difficulty to get an actual ending screen.
Pac-Man (Namco)	Loops after stage 1 (and beat high score, of course)
Palamedes	Win a tournament to get the credits
Pictionary	Finish a single game
Pinball	Get 200,000 points for the flippers to disappear then reappear
Pinball Quest	Finish RPG mode
Pinbot	Beat the high score of just under 10 million
Pipe Dream	Loops after stage 16 on game B
Pirates	Retire with the highest rank of King's Advisor
Popeye	Loops after level 3
Pro Sport Hockey	Win a Super Cup
Puzznic	Clear Puzznic and Gravnic
Qix	Must beat high score of 100,000 points
R.C. Pro-Am	Loops after level 24
Race America	Best ending is not necessary
Raid on Bungeling Bay	Just need to beat round 1 of game B
Rally Bike	Game ends after playing each stage twice
Rampage	Loops after 128 stages
Rampart	After you see a screen saying "you won the war," you'll start a new level where a single enemy ship approaches waving the white flag. After this you'll get a "The End" screen saying you completed the game
RBI Baseball	Finish the season with a 9-0 record
Remote Control	Win a single game
Rescue: The Embassy Mission	Beat mission Jupiter
Ring King	Beat the world #1
Rock 'n Ball	Beat all modes. Specifically: Mode 1: Beat the high score. Mode 2: Get at least the final secret code. Modes 3 & 4: Beat all the sub-modes. Feel free to use the codes once you've unlocked them.
Roger Clemens' MVP Baseball	Pick an NL team (they play 6 fewer games)
Rollerball	Get 1 million points to get the credits
Rollerblade Racer	Get 5000 points to compete in the final race, after which you get the credits for a third place or better finish (10,000+ points)
Romance of the Three Kingdoms	Win the fifth scenario
Romance of the Three Kingdoms II	Win the sixth scenario
Roundball: 2 on 2 Challenge	Win the tournament
Seicross	Loops after level 6
Sesame Street: 123	Beat each game in each of the two modes
Sesame Street: ABC	Beat each game in each of the two modes
Sesame Street: Big Bird's Hide & Speak	Beat all 6 levels
Sesame Street: Countdown	Finish each mode
Shooting Range	Get 40,000 points to win the gold medal
Short Order/Eggsplode	Complete a 10 story burger on short order and 60 bomb round on eggsplode
Side Pocket	Must get 7,100 points to get the final trick shot to appear, which leads to the credits
Skate Or Die	Compete in all events
Ski Or Die	Compete in all events
Sky Kid	Loops after mission 26
Sky Shark	Loops after stage 5
Slalom	Beat all 8 races on each of the 3 mountains
Snoopy's Silly Sports Spectacular	Go through "1 play total game" and win a medal
Soccer	Win a single game
Solomon's Key	Continue code is fine to use, since it's on the poster that came with the game
Spot	Win a game versus the computer
Spy Hunter	Get to the loop point (after each season, ~15 minutes?)
Spy vs. Spy	Beat the computer on any level
Sqoon	Loops after phase 8
Star Trek: The Next Generation	Achieve the rank of Captain
Stealth ATF	Loops after stage 8
Super Dodge Ball	Win world cup play
Super Jeopardy!	Win the finals (three games)
Super Team Games	Win all 4 events in 1 player mode
Tag Team Wrestling	Must beat the champions' mark of 35 victories
Tecmo NBA Basketball	Complete a season and win the NBA Finals.
Tecmo Super Bowl	Complete a season and win the Super Bowl.
Teenage Mutant Ninja Turtles: Tournament Fighters	Playing on normal is fine (even though the credits are only on hard)
Tennis	Win two matches on any difficulty to win the trophy
Terra Cresta	Get to the loop point (third boss?)
Tetris	Beat 9-5 on B-type, and the high score on A-type
Tetris 2	Start on level 30 (to make it faster). Keep playing until you reach "The End" and the game goes back to the title after level 80
Three Stooges	Get at least $5,000 to get the worst ending. You can deliberately game over once you have the money and you'll still get the ending.
Tiger-Heli	Loops after stage 4
Touchdown Fever	Play and win a tournament.
Town & Country Surf Designs	Finish stage 10 of wood and water rage
Track & Field	Compete in all events and beat the high score
Track & Field II	Play Olympic Mode and reach the closing ceremony after the 8th day
Ultimate Basketball	Win the tournament
Urban Champion	Loops after 3rd fight.
Vegas Dream	Must win $10 million
Volleyball	Win a single game
Wario's Woods	Finish 100 rounds of Game A or B
Wayne Gretzky Hockey	Win a game versus the computer
Wheel of Fortune	Win a single game
Wheel of Fortune: Family Edition	Win a single game
Wheel of Fortune: Featuring Vanna White	Win a single game
Wheel of Fortune: Jr.	Win a single game
Where in Time is Carmen Sandiego?	You must complete all 80 cases until you're retired. It's not enough just to catch Carmen.
Wild Gunman	Loops after stage 1. So just beat at least one round and the high score for each mode.
Win, Lose or Draw	Finish a single game
Winter Games	Compete in all events
World Champ	Compete in all events and get the gold medal in each
World Class Track Meet	Win the tournament
World Games	Set a new world record in each event
Wrecking Crew	Beat all 100 stages.
WrestleMania	Win a tournament
WWF King of the Ring	Win either the WWF Championship or the King of the Ring tournament
WWF Wrestlemania Challenge	Select "yourself" and defeat all the other wrestlers
WWF Wrestlemania: Steel Cage Challenge	Win the WWF Championship
Xenophobe	Loops after stage 8
Xevious	Loops after stage 16
Yoshi	Beat level 16 on Game B (to get the pineapple final fruit)
Yoshi's Cookie	Beat round 10, stage 10