We could also open a forum thread to discuss this and get other folks' take - there are some seasoned designers whose opinions I respect that would probably weigh in.
Sorry, I don't check my wall very often.
I understand the 'rule' that with abandonment on in a large board there should be attack limit - otherwise the midgame becomes an exercise in moving stacks around and boardwise unit density absolutely tanks. I've played games like that and they are more work than fun.
It's likely that there's some 'sweet spot' for an attack limit that's some ratio of the total number of territories on the board, I'd guess - on Colonies it just feels like 12 is way too low for the size of the board. Didn't I play a couple of games on it with you right before I wrote my review? I feel like most anybody who plays it would feel this way.
Tell you what, if you can find a couple of like-minded souls, can we put together a couple of test games with, say, 4 or 5 players and tweak the attack limit and see if we can find a better number? I don't know if that's possible in the board design paradigm here, it's been literally 10 years since I last opened the board designer. If you're interested in continuing this conversation, can we take it to PM? There's a visual indicator of a new PM in the UI; I'll forget to look at my own wall for weeks at a time.
http://www.wargear.net/boards/view/Colonies/Ratings
Turns out my review was not as detailed as I thought I recalled; the comment below is more thorough. But other reviewers have specific comments.
I don't really care for attack limits, particularly on large boards. That's ultimately your call to make as designer, but you played with me in at least one of the recent games on that board that was really hampered quite dramatically in the endgame due to the attack limit so you should be well aware of the limitations it imposes, I'd think.
Re Colonies - I felt I left a fairly detailed review. For a first effort, it's a pretty tremendous start - I LOVE the graphical style & design. Would love to see you continue creating boards. There are two things, mainly, for me.
One is actually a few small things. The continents are imbalanced (dramatically), the territory pathing isn't great (that is, it lacks connections where one might expect to find them), and there are some foibles to the graphical indication of oversea borders. And I find the visual indication of which colonies correspond to which main continents very difficult to read. Together all this adds up to minor nitpicks on what would be an otherwise pretty good interpretation of a world map. The map image is so good I'd probably round up to an 8 at this point in the evaluation.
And then the 12 attack limit makes the board virtually unplayable.