Yes I have it and the core gameplay is more in-depth than that of Isaac. That said, you can only ever use one gun at a time, there isn't much in the way of passive and active bonuses interacting with each other like they tend to do in Isaac. The systems are much simpler in general, without pills, cards, bombs, runes and all these sorts of things. I think I will be playing both for quite some time still, I haven't made it all that far into the gungeon yet. Your skill definitely matters more in this game compared to your mastery of arcane rules and encyclopedic knowledge of items.
