Thank you Ashley.
I did the project > tools > Stats thing..
I got this result..(partial)
===================
Layouts: 110
Event sheets: 25
Total number of events: 6740
Total number of conditions: 9706
Total number of actions: 10233
Object types: 448
Families: 1
..
Estimated peak memory usage is 832 mb due to largest layout 55
Top 10 layouts by image memory usage
55: 832 mb
59: 806 mb
57: 805 mb
58: 805 mb
40: 780 mb
53: 779 mb
56: 779 mb
51: 778 mb
52: 777 mb
...
==========================
After reading the memory usage guide and the 'Remember not to waste your memory blog',
.. I guess I am in trouble.
Still, a little surprised that the same game runs on Android (tablets and phones) which have less memory on them than an iPhone8 with 64GB running iOS14.3!
I have been looking to see what Apple says about Safari limits but so far coming up empty.