UPDATE #2: Dark Matter has been removed from sale on Steam. A notice reads: "Currently there is a known issue at the end of the game. The developer is aware of the issue and they are working on a patch as a solution."
UPDATE #1: GOG.com has gone a step further and offered refunds to people who bought Dark Matter believing it was something more than it was.
"It's come to our attention that the gamecard for Dark Matter was not quite specific enough about the nature of the game and, as a result, it may be that some people bought the title with some misapprehensions as to how the game's story would end," GOG explained. "Since we don't ever want to sell a game to someone because they believe it is something that it is not, we wanted to let you know about this and let you know what we're doing to make it right.
"If you bought Dark Matter before 21 October 2013 at 15:00 GMT (when we updated the description to where we feel it adequately reflects the game) and you feel that the game wasn't as promised to you, please contact Support and they'll be happy to offer you full refund to your card or, if you''d prefer, games of equal or lesser value to the sale price of Dark Matter (which is $13.49).
"We're sorry if anyone who bought the game isn't happy with the way it was represented, and we hope this makes it right for you guys."
ORIGINAL STORY: "A more conclusive and satisfying ending" to Dark Matter is coming, publisher Iceberg Interactive has insisted.
It's a response to the surprise "To be continued..." ending the Metroidvania-style game came to after a handful of hours of play. Fans complained (via GameInformer) that they were mislead into thinking it was a full game.
This lured publisher Iceberg out to explain the situation. In a nutshell: by not being successful on Kickstarter, Dark Matter wasn't able to achieve its original full-game goals. Thus it's become episodic, although future episodes are dependent on the first episode's success.
"We would like to stress that the game is exactly as described on Steam (including that it contains 14 levels) - it is simply not true that the game is unfinished, or unplayable," Iceberg CEO Erik Schreuder wrote.
"It is true however, that at present, the end of the game may cause confusion and is not satisfactory. We sincerely apologise for this, as it is not of the standard we would expect.
"We are working to offer a more conclusive and satisfying ending to the game as we speak and expect a fix to appear as soon we are able to."
Dark Matter costs £10.79 on Steam at the moment - a slight reduction to its normal £11.99 price.