I was not planning to make serious attempts in the contest, but I have writen heuristic bot.
It mades roughly 6 actions ... defending mine, "defending neutrals", colonize neutrals, centralize, attack exposed enemy, flow attack (when leading).
All (defences) were based on ships on the air arrival calculations. Colonizing used minimum return turn for selecting the best planet to attack and the attacks were planned to arrive to the neutral at the same turn. All ships were send directly to the target.
I have looked at the actual score and expected performance around 500. I was surprisingly rated around 80.
This encourages me. I have started codding of more serious bot using BItsets for planets the the given distance making plans for the whole game (but only with small horizon filled) with time management, reading input only till all infomation is known... calculating planet influence as a dimension for colonizaction optimization but I got time for programming only occassionally so the project was never compiled.
Instead I have looked at the prerformance of my heuristic bot and tried to improve the heuristics a bit. I have changed centralizing not to use one skip, but rather centralize with shorter flights (minimum of some cost function). This was done when I felt to position around 120 and the improvement moved me to position 35, then I start drifting to positions around 80.
After chaniging the map generator I started losing, as simple centralizacion to planet nearest opponent does not work well on line symmetry maps. (I was losing mostly on maps with frontline consisting of several planets till that).
I never considered planet sizes for my defense heuristics. I never considered opponent's options. Instead I have tried to calculate the number of ships required for defense if opponent issues an attack (my bot used same calculation for determining targets). I have added "shared reserve" calculations. I hav eposted the third version of bot with that and it returned to positions around 80.
Early after posting I find the calculation was wrong and it actually does not calculate required defense. I have removed the bug, but the bot was absolutely passive and won around 10% maps against the posted "buggy one". The situation when the bot performed well due not doing what was intended made me nervous and I have tried to made better version of it.
I wanted to modify the bot not to be as eager as it was I have added global measure ... when having greater total growth planned ... not to invest to other neutrals losing due to small total number of ships. Meanwhile I have found several other "bugs" in the code ... when capturing opponent's planet, I was not supporting it until turn it becomed mine. When I have planned to attack neutral later, I have started centralization to that planet. ... I had about 5 candidate bots each improved some way. Seems I have not chosen the best, as now I am around 250, while not changed bot's skipped me (and a lot of crazy moves could be visible ... so letting the buggy one was probably the best option

).
I modified colonization in the way ships are moved closed to the neutral to let them available elsewhere if the attack would be canceled.
There were other paths leading nowhere as well ... sending troops in path optimised to "as short" skips as possible does not improve the ship availability.
I have added ... attack nearest planet mode for the case I am "winning" (was intended for the case higher number of ships but smaller growth rate, but rarely invoked in that case). This mode probably requires shortening the fleet skips. It works better on maps with distant players.
My heuristics bot started every turn almost from scratch without considering previous turns.
This is why sometimes the capturing neutral plan is abandoned even with 0 neutrals on the planet

.
Having buggy eager version is better than having "defender" version with bugs in the main line ...
I like the iouri's method how to not went to passivity. Just consider several options and calculate their best "investment return".
So ... next time I would probably not participate at all ... participation without serious time plan ...