Yes, God is omnipotent (all-powerful). This does not mean He can do the logically impossible, such as create a square circle. It just means if it can be done, God (God-Consciousness) can do it. There can be nothing more powerful than God-Consciousness because nothing exists or can exist that is not God-Consciousness. So, while you may be able to dream up some way in which God is not omnipotent, either you are asking for something which is intrinsically impossible and, therefore, nonsense, or you are dreaming up something that is unreal and does not and cannot exist.
There has been much argument on this point about whether God is or can even be all-powerful. Just think about it. If absolutely everything is held in God-Consciousness, then anything that exists or could exist is within the power of God to create. If something like the square circle is logically impossible, then God cannot create it either. This does not reduce His power. God-Consciousness can do whatever He can conceive of doing. Since there is nothing that can be conceived where God-Consciousness is not the one conceiving it, then nothing more powerful can exist. So, there is no need for any definition of what omnipotence means other than it is as powerful as it gets – however powerful that might be!
(Parts of this blog are quoted from The God Franchise)