While Steam allows you to search for games through a variety of means, including keywords, the whole process is a little bit fiddly. Due to Steam's user-driven approach to keywords and tags, there's a whole bunch of them that essentially mean the same thing, yet are spread across games in a haphazard and almost random way.

For example, if you were to search for "3D" and "platformer", you would indeed get a lot of 3D platformers, but you would unfortunately not get any games that might just have the "3D platformer" tag. For bigger games this isn't too big of a problem as they often have an excess of keywords, but for indie games with drastically smaller communities, this can often be the difference between being discovered or completely ignored.

In order to combat this problem, Steam has now unleashed the Query Expansion system into testing. As the name itself would imply, Query Expansion essentially broadens your search to include all of the terms that directly relate to what you're looking for. So if we use the example above, simply putting in "3D platformer" would also give you results for games that have both the "3D" and "platformer" tags.

Things do get a little bit more complicated with some terms as while they may be related, one doesn't necessary involve the other. The one example Valve gave is that the "dark" tag doesn't imply the "Lovecraftian" tag, even though both of them appear together quite commonly. These situations will need to be handled on a case-by-case basis, so if you do decide to give the new system a try, make sure to leave some much-needed feedback.

You can read a more about Query Expansion, as well as figure out how to join the Steam Labs Experiment program yourself, over at Steam.