Congrats on the win! Sorry about the lack of a proper victory screen, this was a jam game so that's how it goes haha. The higher tier cards are pretty rare, but the ones you mention aren't quite as hard to come by as for example the doomsday/tiger missile. You're totally right though that the game is a bit heavy on luck at the later stages. Stacking your deck with topdecks and keeping it small helps though.
If you're interested in seeing more games like this, give me a follow if you'd like. There is a sequel in the works :)