> A custom engine is never _needed_ technically speaking since COTS engines are often customizable to the point where you can do anything you want with them
Yeah, no. You can make a lot of things with an engine, and if you don't already have the necessary talent to make a custom engine you probably should just not.
But there are certainly games which would not exist as "Just use COTS" games. The first which comes to mind is Outer Wilds.
Outer Wilds is running a tiny solar system model. Such a model isn't stable for very long even if you had a lot of compute power which a video game console does not, but in Outer Wilds there's an excuse for that [spoiler] the sun is about to explode, it's a time loop game. Still, this is a heavily specialised engine because normal games centre on the camera or player, Outer Wilds can't do that, the model would explode almost immediately if you do that, so the centre is the sun at all times.
I didn't know that. Although it seems as though they're sufficiently far outside what its makers thinks Unity is for that their attempt to go to Unity 5 had big obstacles. Thanks for correcting me!
[Also, another way I was wrong: to make Unity work the centre of the world is the player, and so the universe is implemented in reverse, your orbit around the sun is calculated with you at the middle, this works correctly in our actual Einsteinian universe - no position is privileged, there is no "center", but it would be crazy to do the maths, for the short time Outer WIlds needs it works well enough with their simple Newtonian physics model]
Yeah, no. You can make a lot of things with an engine, and if you don't already have the necessary talent to make a custom engine you probably should just not.
But there are certainly games which would not exist as "Just use COTS" games. The first which comes to mind is Outer Wilds.
Outer Wilds is running a tiny solar system model. Such a model isn't stable for very long even if you had a lot of compute power which a video game console does not, but in Outer Wilds there's an excuse for that [spoiler] the sun is about to explode, it's a time loop game. Still, this is a heavily specialised engine because normal games centre on the camera or player, Outer Wilds can't do that, the model would explode almost immediately if you do that, so the centre is the sun at all times.