Sergey Galyonkin, who runs Steam Spy, is the internet’s top man for getting data on Valve’s marketplace. Which makes his summary of 2015 salesoverall sales, not just the seasonsal Steam sales—some interesting reading.

While his data isn’t 100% accurate (it’s gathered using “statistical analysis” rather than actual figures from Valve), Steam Spy is for the most part pretty damn close, so disclaimers aside, the numbers are worth looking at.

Galyonkin’s key findings are:

That despite fears over an “indiepocalypse”, ie the service being buried beneath an unsortable mass of new video games, over the latter half of 2015 the number of new games being released on Steam actually flatlined.

December is the dominant sales month, obviously, but April was #2 in terms of revenue. Thank Grand Theft Auto V’s PC release for that.

A collection of monthly sales charts from April onwards shows that people sure loved Fallout 4, GTA V and Valve’s games. And ARK: Survival Evolved. Check November’s charts and you’ll also see one of the reason’s Assassin’s Creed is taking a break in 2016.

And finally, the annual sales chart comes in two flavours: revenue and units sold. The revenue one has some problems, not least that it doesn’t actually cover all of 2015, but take a moment to look up and down the one on the right (units sold): it reads like a pretty decent GOTY list, which is neat for a sales chart.

You can read the full rundown here.