Before the Sega Genesis took the world by storm, the Master System was the Sega console to own in the late 80s. Originally released in Japan in 1985, the Master System made its way to North America in 1986 and was an alternative to the Nintendo Entertainment System. But while Nintendo's console saw massive success with hits like Super Mario Bros. and The Legend of Zelda, the Sega Master System only achieved mild success in comparison. The console had fewer games than the NES, but was able to find a base of supporters in territories outside of North America. But by the time the Sega Genesis was ready to launch, the company had moved on from the Sega Master System in hopes that their newer console would be a better competitor against Nintendo's hardware.

Since the end of the Master System's time on the market, games that were released for it have become gems for retro collectors. But like other consoles, some games have become a lot more elusive than others, fetching higher prices for their rarity. For any Sega fan, these games are bona fide treasures from the history of Sega before the 16-bit console wars began, but they're prohibitively difficult to find. Here are five of the rarest Sega Mega Drive games that you may never get to own.

5 Alex Kidd in Shinobi World (Blue Label version)

Parody is the best flattery

One of the original mascots for Sega was Alex Kidd, a character that could use different powers when transforming his appearance. He starred in a few games released for multiple Sega platforms, but he never caught a wave of popularity in the same way that Sonic the Hedgehog would later with the Sega Genesis. But before the Genesis was on the market, Alex Kidd had a game that was a parody of the Shinobi series that was going strong in arcades. Alex Kidd in Shinobi World is an action game that plays a little differently from other Alex Kidd titles, and more closely resembles what it is spoofing. The game is fairly short and simple to play, with Alex Kidd using a sword to take out enemies and find treasures within chests that are placed throughout the stages. Boss fights take place near the end of each act, but the stages are inspired heavily by the Master SYstem version of Shinobi.

While the game received a positive reception around the time of its release, it has mostly been forgotten by many people. Today, loose copies of Alex Kidd in Shinobi World can be worth around $80, with a complete-in-box copy being worth a lot more. The specific version that is valuable to collectors is the blue labeled cartridge, which is a little different from most Master System games that have a red label on them. Complete versions of this type can be priced anywhere from $150 to $300 in most online auctions.

4 Power Strike

Vintage vertical shooting

Sega has a history of arcade games that are shooters, often with varying kinds of gimmicks or themes to them. Power Strike is a series developed Compile Corp for the Sega Master System, which included two games for the Master System and one release on the Sega Game Gear. The first game for the Master System was originally released in Japan under the title Aleste, but was renamed Power Strike for its international release. Unlike the Japanese version, this North American version of the game has no anime storyline and one less level to play through. The gameplay is straight-forward, with tons of enemies to shoot at on a scrolling screen.

Unlike other Master System games, Power Strike was originally a game you could only get through mail-order. It's the first Master System title to be available like this as a limited edition, and was later sold in retail stores. Because of that, the first run of Power Strike is more valuable to collectors than the one that came later. Loose cartridges of the game can go for $90 alone, while complete copies with their original box are worth around $200. Although the North American version isn't as content-complete as the Japanese version, it's still a valuable collectible.

3 Golden Axe Warrior

Action from a different perspective

The Golden Axe games are synonymous with high fantasy and brawlers. The arcade games and additional releases for the Sega Genesis are among Sega's most iconic releases, especially within the brawler genre. But another Golden Axe game for the Master System took a very different approach.

Golden Axe Warrior was released on the Sega Master System in 1991, and had very different gameplay than the rest of the series. Borrowing elements from Nintendo's The Legend of Zelda series, Golden Axe Warrior puts players into a top-down perspective for a new action-adventure experience. Although the antagonist of the game is still Golden Axe series baddie Death Addler, you'll be battling his evil forces very differently. Exploring dungeons, solving puzzles, and slaying enemies with some mild fantasy RPG elements makes this a unique release within the Golden Axe franchise.

Golden Axe Warrior is one of the rarest Sega Master System games around. It hasn't been released often, but was included in the release of Sonic's Ultimate Genesis Collection as a bonus unlockable. But hard copies of the game on the Master System are hard to come by. Loose copies of the game are worth more than $150 alone. But a complete copy in its original box is valued over $350, and has been known to seel for over $700 in auctions hosted online.

2 Phantasy Star

Real old-school RPG

Most people, when they hear the name Phantasy Star, think of the more recent iterations of the franchise. This mostly includes the Phantasy Star Online titles that incorporate online multiplayer. But the series didn't start off as anything like that, and was actually a more traditional role-playing game on the Sega Master System. The first Phantasy Star game was released in 1987 for the Master System, and is considered one of the earliest RPG games released on home consoles.

Like other games in the genre of that time, Phantasy Star uses high fantasy themes and traditional turn-based combat, but it has other elements to it as well. Exploring around is done from a top-down perspective, while battles and interactions within dungeons are done with a first-person view. Besides fighting, players can talk with enemies and try to negotiate with them, avoiding combat altogether.

For many, it doesn't get any more classic in the genre than the original Phantasy Star game. At the time, Sega started development on the series following the success of Dragon Quest, which released on the Famicom in 1986. Phantasy Star went on to have multiple sequels on the Sega Genesis, and the series underwent a major change years later. Loose copies of the original game for the Master System are valued at $75. But if you manage to find a complete copy of the game with all of its original contents, it can be worth nearly $300.

1 James Buster Douglas Knockout Boxing

An expensive haymaker

The rarest and hardest game to find in the Master System library is James Buster Douglas Knockout Boxing, for a number of good reasons. Originally, the game was known under the title Final Blow, which was released in arcades by Taito in 1988. But when it was released in North America by Sega, it had a rebranding and gained the license to use the name of heavyweight boxer James Buster Douglas, making it one of the first major sports games for a Sega console. At the time, James was very popular in sports circles as the man who defeated Iron Mike Tyson, which came with a lot of endorsements and deals, including licensing his name for the game. At its core, James Buster Douglas Knockout Boxing is almost exactly like the original Final Blow release, with a few minor changes to include James and a parody of Mike Tyson as fighters.

There was a Sega Genesis version of the game that was a lot more common than the Master System version. This was mostly due to the game being featured as part of the "Genesis Does" campaign to promote the release of the Sega Genesis. By all accounts, the 16-bit version of James Buster Douglas Knockout Boxing is better overall in terms of visuals. However, some players feel that the gameplay in the Master System version feels much better to play. Regardless, the game has become the rarest Sega Master System release and is incredibly difficult to find. Loose cartridges of the game are worth over $350 alone, while complete-in-box versions of the game are heavily valued at nearly $1,000. Some auctions online have reportedly sold the game for around $2,000 at the time of sale, making for one really expensive Master System title.

The jewels of the Sega Master System

While not the premiere console that Sega is mostly known for, the Master System has an interesting history. The games released for it can often be seen as precursors to what would eventually come with the release of the Sega Genesis. As a competitor to the Nintendo Entertainment System at the time, it wasn't the system that the company needed to remain relevant at the time, which caused them to move on towards a new era that changed gaming history. Within its library are games that aren't the most critically acclaimed or universally played among gamers, but they are still gems for collectors that have an affinity for gaming history. You might be a big fan of Sega and their storied history, but you might have a hard time gathering all of these Master System games for a collection.