They changed to Unity for the iOS version.
The first & very succesful PC version was done with gamestudio and was featured on steam.
But now they are working with Unity, because it works for them.
Thatīs the only thing what counts imo: Use whatever works for you.
For instance, I wouldnīt use GS or Unity for a 2D adventure. I would go for other solutions, that are build towards my goal.
For prototyping ideas I use Gamestudio quite often, because Iīm used to it. But to prototype a physics based game, I use unity for example.
The world is not black & white. You donīt get vanished in nil or end up in hell if you use different engines and tools.
No big bad geek will come and kill you. Believe me.
