I just deployed another optimizations update.
This update manages to give the engine a pretty significant overall speed boost. This does not include the "pause offscreen objects" setting, since I have decided to forgo that for now and try to just make the engine much faster overall instead of having a setting to make it run faster.
There are no new visible features, but:
1) Nearly all games should run faster in play mode. The more static (no movement or behaviors) objects that your game has, the more of performance boost you can expect (Sorry, Starblast). Some games I've tested have a 50% or more improvement.
2) Switching between play and edit mode has been optimized. For most games this hasn't been an issue, but games with lots of objects have had a pretty serious delay when switching that has been greatly reduced.
This update has some pretty serious internal changes to the engine, and although I've spent a lot of time testing, please let me know if you spot any issues I introduced into your games.