New this build: collision cell optimisation for Tilemaps. We had previously added a collision cells optimisation, but it did not apply to Tilemaps - they still counted as one big object covering the whole layout, and therefore were in every collision cell, and would always check every collision rectangle when testing collisions. Tilemaps were still optimised to avoid having to collision check every tile, but with large games using tilemaps this would still gradually get slower with bigger games as it had to do more and more collision checks. Now the two have been combined: internally the Tilemap object now also breaks up the tiles in to collision cells and only collision checks with the nearby cells. This should vastly reduce the number of collision checks done in large tilemap games and improve performance, especially on mobile devices dealing with large levels.
This change did involve a fairly deep overhaul of the Tilemap object, so please watch out for any regressions or new bugs. If you find any issues please post them to the Bugs forum following all the guidelines - and as ever, try to reproduce the problem in a new project.
The Turret and LOS behaviors can now also optionally turn off the collision cells optimisation. In some specific cases, over very long ranges/distances (e.g. 10000 pixels) it could actually reduce performance since it would have to check so many collision cells, which is extra work it didn't have to do before. It's strongly recommended to leave it on since in most cases it's likely to be a lot faster, but if you are having performance problems with large layouts it might be worth experimenting with.