Hey Jason,
It is unlikely that collisions are the source of lag on your device.
The issue you are describing is likely caused by the device you are running Perfect Vermin on being below Perfect Vermin's minimum system requirements.
If this does not seem to be the source of the issue and your device is above Perfect Vermin's minimum system requirements, please contact us (preferably over our Steam community discussions but Itch also works) and we will look into the issue immediately.
-Maceo (Game Designer/ Artist)