But using the x2 marathon mod and 25% Eureka mod is one way to fix marathon, at least partially. The problem, insofar as I'm concerned, is that in non-modded marathon, the costs of districts, buildings, units, etc. are all increased almost in direct proportion to the increased tech/cultural tree costs. By using those mods, you make the tech and culture trees disproportionately longer compared to costs (which is a good thing). That fixes the problem.