♫ Eric Herman ♫
I like elephants. I like how they swing through trees.
What about the issue of the cards being different sizes?
That only applies if you have the Z-Man version of the base game. And even then, it only applies for 14 new Event cards and 6 optional Darwin Event cards. Everything else (which is almost everything else... and it's quite a lot) can be played on its own and doesn't mix with any of the old components.