Markus "Notch" Persson is "selling" his first video game since Minecraft.
The Swedish developer is requesting payment for Cliffhorse in the virtual currency Dogecoin, although it can be downloaded without doing so.
He has tweeted that the game - in which the player controls a galloping horse that can chase an animal-skinned ball - only took him two hours to create.
Other posts indicate the game is a deliberate spoof. However, that has not stopped people from paying for it.
Mr Persson noted that his initial tweet advertising the "early access" title had raised more than $100 (£60) in the hours after he posted it.
He later created a website to promote the game, which pointedly states that there is "no guarantee of future updates".
Scott Grill, a writer for the Examiner news site, is among those who have interpreted Cliffhorse as being a means to criticise the sale of other "early access games that have been appearing on Steam and other places where very little work and semblance of a game exists".
Examples of controversial uncompleted PC games put on sale include:
- Towns - a city-building game sold for $14.99 via Steam Greenlight, whose developer abandoned plans to complete it himself after reporting weaker than expected sales.
- The War Z - an open-world zombie-themed survival game that cost $15, which was pulled from Steam after complaints that it failed to offer promised features. It later returned under a new name but continues to attract poor reviews.
- Earth: Year 2066 - a sci-fi game costing £19.99 that was removed from Steam following a campaign on Reddit that alleged customers were being sold a "broken" title.
The controversy has prompted the US-based owner of the Steam platform, Valve, to update its Early Access Games FAQ last week to state: "You should be aware that some teams will be unable to 'finish' their game. So you should only buy an Early Access game if you are excited about playing it in its current state."
However, an English gamer known as PewGeminiLive suggested some people were reading too much into the release.
"Notch and I came up with the idea during one of my live streams on Twitch while playing Skyrim," he told the BBC.
"The game was a simple joke to make fun of the "horse mechanics" whilst on a cliff."
The world-building game Minecraft was itself an "early release" game - sold as first an "alpha" and then "beta" branded title over the first years of its life.
It has gone on to become one of the best-selling and best-reviewed games of all time.
This is what, perhaps, convinced people to pay for Cliffhorse despite the fact it appears to be a spoof.
Nonetheless, one UK games blogger was left dispirited by the reaction.
"It's an obvious joke and from what I know of the Unity Engine, most of the assets from the game are already defaulted in-engine, and all Notch had to do was look through the asset store and download a free horse model," wrote Justin Ross on the Pixel Gate site.
"Really no work whatsoever had to go into making this game, and there's even people spending money on this thing. That's crazy."
Mr Persson's stunt was released on the eve of the video games industry event, E3.
Although the Los Angeles expo tends to focus on console titles, there is also a PC-themed spin-off - the Nvidia Gaming Expo - organised by the computer chip-maker, which runs over the same period.