I only have a couple games in on GS so this is far from a comprehensive analysis, but I'm noticing that the balance between rising sea levels and flood barriers seems a little off. Namely, you are barely getting the tech to build the barriers by the time water is rising, and the cost of the barriers is sometimes such that you just can't build them fast enough. So instead of it being an option on if you choose to spend the resources on the barriers or not, you almost have to just except the loss of territory. I typically play between Immortal to Diety level, standard maps, standard time. Usually by that stage in the game I'm even with or ahead of most civs in the game except for possibly one runaway that I'm chasing. In my current game as Dido on an islands map, I had conquered Spain who started on the same land mass as I and he had quite a bit of low lands, including his capital, Madrid. I conquered him before the seas started rising and before I got the flood barriers tech, and started to build them immediately when I could. In my original capital Tyre, I only had one tile and built the barrier with no problem. Another of my original cities had 2 tiles and built the barrier in time to save 1 tile but not the other. And in the conquered Spanish cities...ugly. None of them completed in time, have lost 4-5 tiles so far, and I think Madrid is going to sink into the sea shortly with the last rise of the ocean. Yes, a former capital is going the way of Atlantis. Not sure what that's going to do to the Victory Conditions when it just no longer exists so curious to see what happens there. So as far as balance, the issues I see are: - Sea levels start going up to quickly relative to when you get the tech to offset. - Production costs of barriers are potentially too high. Currently, it seems that the value is tied to how many tiles need to be protected. In my above example, I think Madrid had 5-6 tiles that needed to be protected, so it was around 2100 hammers to build the flood barrier. Madrid was also on relatively flat land so production wasn't great, but at a moderate 50 hammer/turn production you're looking at 42 turns to build a flood barrier, which seems pretty ridiculous. Only Wonders should take that amount of turns for an average developed city to produce. Tyre's was relatively easy with only 1 tile. I didn't catch the total hammer cost before I completed it, but I think it took around 8-10 turns and Tyre has pretty decent production for an islands map. - Even after I permanently lost the 1m tiles, I didn't see it recalculate and adjust the flood barrier production for the city, i.e. it was still building the flood barrier around the lost tile anyway instead of focusing on the tiles which could still be saved. A couple of initial thoughts/ideas: - Delay or slow the sea level increase. It starts fairly soon after coal plants start getting built, and it goes up fast. About every 7-10 turns in my current game on Standard speed, and you can hardly build a one tile flood barrier in that time. - Build floor barriers one tile at a time, instead of the entire flood barrier for a city being calculated and built at once. This allows you to prioritize which tiles to save, and you can also completely finish one and then move to another if you have time. Currently, you're trying to build the entire thing and losing your 1m tiles while your 3m tiles aren't even being threatened yet. This compounds if your 1m tile happens to be a hammer tile, and once you lose it it pushes out the finish time of the flood barrier even further. - Add some earlier floor barrier (dike?) that can be constructed with an earlier tech and later upgraded for a cheaper cost. That earlier barrier can be less effective, or only built on the 1m tiles, or something along those lines, but if it shortened the build time of a full barrier for 1 tile down to 4-5 turns later it would then be viable to actually save tiles if you choose. Just some initial thoughts/observations. I gave up on most of the barriers in this game because I clearly had no chance to build them before the land was lost, which was kind of annoying. Oddly, I have a Harbor floating in the middle of the ocean and not touching any land that still seems fully functional now. It's a fair mechanic to choose whether to divert production into flood protection or not, but only if it's actually a viable choice consistently. Initially, this looks like something that you're just going to have to accept losing tiles to more often then not, which is kind of annoying.