I just deployed an update that optimizes the engine to better deal with loading larger (>10K objects) games. I have a few more optimizations in progress, but I would like to roll them out bit by bit so that I can test each one in isolation. This update has the following updates:
1) Loading is smoothed so that even with a large number of objects, the engine will not hang and fail to load
2) Initial level setup is optimized so that the level will display faster (this may only be noticeable for large levels)
3) A few minor performance improvements to the physics engine
The next update will have a new game setting "pause off-screen objects" which will stop running objects when they are no longer visible. This will offer a way to get a huge performance boost for larger-sized levels. This is a feature that I added a long time ago, but subsequently removed since it caused problems for people who expected their objects to run all the time. I think having as a setting will be a reasonable compromise. Thoughts?
These updates have been tested pretty well, but please let me know if you find any issues.