One of the biggest problems in creating a modern computer game is writing the game engine. You may have the best ideas in the world, and the talent to implement them, but if you don't have a game engine you don't have anything. For this reason many companies have developed game engines that they are licensing to developers to ease the menial low-level tasks, allowing them to concentrate on what actually matters, ie. the content. Examples of such game engines include the Unreal Engine, id Tech, CryEngine and Unity.
Especially Unity, with its accompanying IDE, has been designed from the ground up to make it as easy as possible to create 3D (and nowadays also 2D) games. There are wonderful demonstration videos out there where a developer creates a small but decent first-person shooter from scratch (although using some ready-made geometry assets) in something like 5 or 10 minutes.
While this is great, there is, however, a dark side to all this. In a somewhat ironic way, this actually makes it too easy for people to make 3D games, as contradictory as that might sound.
Or rather, it makes it too easy for people to make "games" that might look somewhat decent in screenshots and carefully-crafted trailer videos, but which are actually complete and utter crap that nobody would play even if they were free.
Don't get me wrong, there's nothing wrong in making and distributing these kind of test projects for free. The problem arises when they start selling them for money on distribution platforms like Steam, masquerading them as actual games, for a quick buck.
Valve used to have very strict quality controls on what could and couldn't be distributed through Steam. This caused lots of complaints because many great games couldn't be sold on Steam just because Valve didn't approve them (perhaps due to lack of time, resources, willingness, or other reasons.) To remedy this problem they implemented the "greenlight" system where users could vote for indie games to be published on Steam. Initially Valve still imposed some quality control on what could and couldn't be published even here, but they have basically completely stopped and just automatically allow publication of whatever gets enough votes.
And thus we get complete non-games that are nothing more than test levels made by some beginner Unity user with zero talent, such as "Air Control".
No, it's not a game in any sense of the word, it's in no way fun to play, its quality is completely abysmal, it's full of bugs, and it has zero redeeming qualities. This is just something that a first-time Unity user could come up with to learn to use the platform, to see how the IDE works.
And it's being sold at 6€.
The unfortunate people who are fooled to pay 6€ for this will get nothing more than a few test levels that are complete crap. (And that's if they are lucky enough that the levels will even load properly.)
IDEs like Unity make it easier to make great games, but it also makes it too easy to sell complete crap and fool people into spending money on garbage that has no playable content whatsoever.