Actually, the customization is higher than ever, from what I've gathered. Heck, now it's even possible to make wormholes that can only allow certain ship-sizes. The problem with this incarnation of Space Empires is, to me, purely the GUI, which is very awkward, illogical and tedious.
The wormhole sizes thing does NOT work as far as I can tell. Quitch: if you've only played SEIII..SE5's customization is going to blow you out of the water.
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Phoenix-D
I am not senile. I just talk to myself because the rest of you don't provide adequate conversation.
-Digger
Neat, it was possible to increase the number of AI's and systems through it. Now I've got 4 Amon'Krie(ish) empires in my game and 3 others. I set the startdate to 25000, never know if it might avoid the 100-turn limit.