Not sure if you intend to keep working on this game. I find it quite entertaining and have played through a number of times now.
I find the early game is much more fun than the late game as the game moves more quickly. A few easy changes could allow the game to play more smoothly as you increase the number of your islands:
- move the updates from the top left corner to appear above the islands (perhaps remove them once the island is selected so that they don't obscure the playing field, battle indicators could probably fade away after a few seconds as you already have the animation to indicate to the player that the battle happened.)
- some indicator that an island is idle (unless there is no available upgrades and already a flotilla)
-an indicator that the island has reached max population (mostly just important when there is already a flotilla, so maybe indicate with the flotilla)
A few other small changes that I think would improve the game, though may not match your vision
- tween ships after each turn rather than just changing their positions.
[Edit: Oops, just realized you do tween the ships. It's pretty fast and they are deleted early when attacking an island.]
- when possible, automatically start on a flotilla if no building upgrade has been selected (this would also help speed up late game)
-add a tech upgrade that allows queuing upgrades
- don't immediately kill extra migrants when it exceeds the population capacity of the island. Maybe, remove some each turn (perhaps as a function of how far over capacity the island is?) Or perhaps put the flotilla in the harbor with the extra migrants. This might make distant islands more useful as well.
-because upgrades and population growth are both dependent on current population size, small sized islands are dramatically under-powered. The workshop does a little to help balance this, but they remain deeply handicapped. Starting out next to only small islands can make the game pretty much unbeatable; conversely starting out near large islands can rob the game of most of its challenge. It's nice that each game is different, but it feels a little too extreme. I'm not really sure what the best solution to this would be, perhaps you could deal with it during island generation. Maybe you could make islands exist in little clusters that usually have at least one large island and several small ones to spread them out more evenly over the map. Perhaps there could be some mutually exclusive upgrades that help regardless of population size, for example instead of building a storehouse maybe you could build a blacksmith that would increase the fighting strength of your troops. In this way, on large islands it might be wise to build a storehouse, but on small islands you could build a blacksmith. Maybe a lighthouse instead of a shipyard that increases the view distance of that island (and/or gives information about the destination of enemy ships)? If you add this, it might be a good idea to allow the deconstruction of upgrades.
-perhaps allow a few more starting teams?
A couple bugs I've noticed
- When a ship is going to attack an island on the turn, but the island becomes captured before the ship can attack, the ship becomes stuck and simply sits at the island's harbor for the rest of the game. If the ship is en route to the island when the island is captured, there is no problem.
- Less annoying bug, when you have an island selected, and reinforcements arrive the population display isn't updated until you click away and click back.
-A couple of times I've encountered a problem where the progress bar for building a flotilla doesn't update, but I don't know how to reproduce it.
[Edit: -when holding shift, and clicking next turn, the info isn't updated. For example, if an outpost is completed.]
Again, very nice game. You have done a good job.