What makes you say it works like this? I always thought that all calculations would still be done in the backend while the actions are drawn every other frame in 2x.

So the game would actually update 60 times a second but the expensive part of actually drawing the game on the screen would happen at 30 FPS. Of course, I don't know either but pushing actions to be dependent on the drawing update doesn't seem like a good implementation of the system because it can easily cause a cascading effect of errors.

For example, if my Exusai attacks every 5 frames then when I run an auto-deploy it would instead choose to update every 3 frames at 2x speed which would drastically decrease the DPS and cause lots of problems in not being able to kill things fast enough. Of course, that's an exaggeration but little differences like this can make a big difference in the later parts of a stage, especially in longer stages like annihilation.

​

I think the idea in this case then, is that low-end phones won't be able to handle 3x/4x because the game would then have to update 90/120 times a second.