On my PC I can have 10,000 objects at 60fps if they aren't doing anything... however I can have only 2,000 objects and fps is down to 30-35 if everything is doing complicated movements, etc.
I'm not sure exactly what would be causing your issue - but I found doing some simple optimistations like having a core condition "is on-screen" made a HUGE difference to performance for doing things like rotating body parts for my characters etc. If they aren't on screen it ignores all of the IK solver chain and just uses "set X/Y" position to lighten the load.
If you have a lot of moving stuff in the layout maybe only "move" them when they're within certain bounds of the viewport maybe, or even destroy them until the player gets closer to the position where they will be required.
In my map layout I have literally over 300,000 objects and it runs perfectly - because it's only drawing around ~500 or so objects at any given time on the viewport - and nothing is moving.
~Sol