Fan made games, or fangames, have been around in the video game industry for decades. Most of the time these ambitious projects are abandoned before completion, and other times, they are hit with cease-and-desist notices from the publishers that own the IP. Fangames that actually see the light of day are typically shut down not long after release, and live on through various file-sharing services across the web.

There have been numerous fangames developed over the years, but the following five stand out as the best and most notable examples to date.

5 Black Mesa

Black Mesa is a rather unique fangame in that it hasn't endured a forced shutdown, and IP-owner Valve has actually shown support for the project over the years. A remake of the original Half-Life game, Black Mesa retells the story of Gordan Freeman as he contends with alien forces from a strange dimension called Xen. Black Mesa boasts highly improved visuals when compared to the original Half-Life, as well as modernized level design. Available on Steam through Early Access, Black Mesa's full release is expected to come in December of this year.

4 Project AM2R

The concept of Project AM2R (which stands for Another Metroid 2 Remake) is simple:  take Metroid 2: Return of Samus and make it look and play similarly to Metroid: Zero Mission on Game Boy Advance. Project AM2r went above and beyond, though, introducing brand new gameplay features, improved controls, and new boss fights.

Unfortunately, Nintendo forced Project AM2R to shut down not long after its initial release, but the story of the game's development has a happy ending. The game's sole developer, Milton Guasti, was hired to work on Ori and the Will of the Wisps as a level designer, and Nintendo eventually went on to release an official remake of Metroid 2 called Metroid: Samus Returns for the Nintendo 3DS.

3 Pokemon Uranium

With an absurdly long development time of nine years, few ever thought Pokemon Uranium would ever release. Then, at the height of Pokemon GO's popularity in the summer of 2016, the long-awaited fangame finally launched, impressing many with its ambition and scope. Pokemon Uranium features 150 brand new Pokemon for fans to collect, in addition to a new region to explore and a much higher difficulty than is typical of Pokemon games. While its overall polish and quality was a far cry from what's expected from Game Freak's official offerings, Pokemon Uranium remains one of the most impressive and fully-featured fangames to date.

2 Sonic: After the Sequel

Sonic: After the Sequel stands as one of the most-downloaded fangames in history, releasing at a time when Sonic the Hedgehog fans were hungry for a quality 2D Sonic adventure. By all accounts, Sonic: After the Sequel successfully captures the charm of retro Sonic games, and for many fans, it was far better than the official Sonic the Hedgehog games Sega was offering at the time. Despite this, Sega has never sent a cease-and-desist letter to Sonic: After the Sequel developer Felipe Daneluz, who has made a total of three high quality Sonic the Hedgehog fangames.

1 Super Mario 64 Online

The most recent fangame on this list, Super Mario 64 Online didn't last long before Nintendo stepped in to shut it down. Even so, the game is notable for adding online multiplayer to Super Mario 64, along with new playable characters like Waluigi, Yoshi, and Rosalina of Super Mario Galaxy fame. Not only that, but it featured competitive gameplay elements on top of allowing friends to collect all of the game's Power Stars as a team.

Besides the fangames listed here, there have been other notable fan projects throughout the years. For example, Project M, a mod for Super Smash Bros. Brawl that attempts to make it play more like Super Smash Bros. Melee, is one of the most impressive and well-received fan undertakings the industry has seen. There's also Skywind, which remakes The Elder Scrolls 3: Morrowind with the Skyrim engine, not to mention Retro Sonic, which was so well-made it led to developer Christian Whitehead working on the critically-acclaimed Sonic Mania for Sega.

Moving forward, it will be interesting to see what other creative fangames are created by the industry's thriving community of content creators. Perhaps game publishers will start being more accepting of these endeavors, and maybe we will see even more fangame creators segue into a proper job in the industry.