The first definition of God is, what we all can see around us – the Universe.
Yes this universe is a simulation (Maya) of Vishnu.
As Maya is a part of Vishnu himself, the universe in physical sense is a body of Vishnu.
As the mind of the universe is the cosmic mind of Vishnu.
The immeasurable intelligence in the universe, is the intelligence of Vishnu.
The unending soul of this universe is Vishnu.