Hi Peter, thanks for the game!
As many I liked the alpha 10, and the others too.
They're bringing a different game experience but I like both.
It looks like you've chosen your way on most feature requests and bonuses so my suggestion may be late.
I was thinking that the cities would not be just the same game with a different river, but rather a different mode of game or layouts. For example:
bonus repartition (you obviously need more tunnels in New York than London!)
max number of lines (7 at London, 8 or 9 at NYC?)
infrastructure bonuses if they come back (a city may prefer or allow capacity over speed or vice versa)
- maybe bring back in different cities the bonuses coming on weeks OR passenger tresholds
- or city-specific bonuses like 8-loops, forks (Paris has a few), high-speed trains that do only the biggest stations and omnibus that do all stations (NYC / Tokyo)... (I know they're hard to code) depending on what you see the real-life cities doing.
A feature I would like, but that may be an entirely different game, is metro-vs-train service (french metro vs RER / Berlin's U-bahn vs S-bahn): you give targets that are quite away from town (think airports) BUT you have a small number (1? 2? 3?) of higher-speed, higher-capacity trains.
OK I'm dreaming right now but hey, perhaps some other peeps would like it?