985k is an incredible score, especially for DL. Well done, Random70! 
How would you rate the current DL, DA, and TA in terms of difficulty in hitting the 1 million mark?
In DA they introduced immense maps which have up to 1000 planets, double that of gigantic maps in DL but DA included changes reducing the economic output you can get from each planet. TA has the DA changes plus it reduced the focus (i.e., when you switch focus on a planet to military, society, or research) from 25% to 20% making the all-factories or all-labs strategy harder. TA introduces unique tech trees so through tech stealing/trading one could collect several bonuses not present in DL or DA.
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Actually, Immense maps were introduced in TA. DA's largest is still Gigantic, which can have over 730 planets. AFAIK, Immense maps in TA produce less than 600 planets though.
I'd say that DL is the hardest as far as mega scores go. In fact, I'm not aware of anyone besides Mumblefratz who has been able to attain that score.
DA would be the easiest in my opinion, which leaves TA in the middle by default.