To be literally "as real in its world (as we in ours)" several things need to happen:

1) its world should be an 1-1 simulated mapping of our world. Perhaps not to its whole extend (e.g. not the whole universe), but to ANY extend that affects the final result.

2) its world should have randomness equivalent to the quality of randomness (not sure if it's perfect) that our world has.

As for "Anything from our world can be simulated" -- that's a bold claim, provided that we haven't simulated ANYTHING at all yet, to the degree of interactions and complexity that exist in our world.

When we simulate the behavior of water in a fluids physics simulation, or the behavior of planets etc, it's amazing how much stuff we leave out. Our simulations are to a full-blown simulation what South Park cut-outs are to a photograph.

Besides, this notion reminds me of the naive 19th century ideas, that they could predict the course of the universe if only they had the details (motion, momentum, weight, etc) of all objects and the capacity to calculate their interactions. QM put a hole in that.