Hi, Joey!
I was thinking of that at the start. I created bitmap for leveldata. And bitmap panels for entities.

Then I found out, that I can not perform pixel operations on panels.
If I render panel to target, this target can not be locked.
And I can not use only BMAPs for storing data. I need panels, to move BMAP along with entity when it moves. And there are also many problems. The worst one - all pixel operations are very slow.

But I always consider this idea in my head, it is just too hard for me to find performant solution.