No, for two reasons.
1. He could create a universe that was an allowable subset. His universe could be massively more powerful, for example, with no limitations on the speed of light or of computation, or at least they're on a scale we can scarcely imagine. For example, you'd probably need a computer on the order of a universe 10^^20 our size, packed with subatomic-sized computer devices just to play a perfect game of chess in a reasonable amount of time.
Perhaps in that universe, that amount of computing power is trivially cheap.
2. If you create a simulation, you can make any rules of physics you want. There are some limits on this, but they're limits on logic and math, not practical implementation. And, overlapping with #1, you could actually code up a more complex universe, e'en if it ran more slowly.
I wrote an orbital simulator as a lad once. I accidentally coded up gravity as an inverse cube law instead of inverse square. The orbits were these lovely trefoil shapes.