TLDR: another suggestion on DLC I'd buy immediately.
DLC 1. Let's say "Waterfront"
What for: to make waterfronts more usable.
Features:
- Zoned ports just like airports with numerous facilities
- Coast guards - works like police for waterfront
- Marine tours - tourist option for rivers and seas
- Marina
- Beach just like in SC4
- Beach fun - water scooters, motorboats, etc
- Unique buildings: a bunch of lighthouses, admiralty, wooden galeon, aircarrier with old jets, submarine
- Maybe even a marine college campus
- Artificial reef
- Diving
DLC 2. Let's say "Heritage"
What for: to fill the historical gap and add fun!
Features:
- Archeology sites on map from different eras. The player can extract them and get a tourist site + get a new unique asset to place somewhere in the city + some relics for a historical museum
Eras can be:
1) Mesozoic - you can find a place with some traces of dinosaurs. After extraction, you're getting a tourist site (e.g. a dino trail), a dino skeleton (that can be placed in your city), and a bunch of things for a museum (bones, teeth, crap, insects in amber)
2) Neogene - you can find a place with some traces of the first people. After extraction, you're getting a tourist site (e.g. a settlement of the prehistoric people), a mammoth skeleton, and a bunch of things for a museum (bones, teeth, primitive instruments)
3) Ancient times - you can find an ancient settlement. After extraction, you're getting a tourist site (e.g. ancient ruins with columns), an ancient obelisk and a bunch of things for a museum (swords, shields, amphora)
4) Medieval - you can find a medieval settlement. After extraction, you're getting a tourist site (e.g. medieval ruins with walls), a medieval statue and a bunch of things for a museum (swords, shields, etc)
5) Modern era - you can find a modern era settlement. After extraction, you're getting a tourist site (e.g. modern era ruins), a cannon, and a bunch of things for a museum (muskets, etc)
6) WWI- WWII - you can find a battle site. After extraction, you're getting a tourist site (e.g. trenches), a tank/plane, and a bunch of things for a museum (mortars, helmets, MGs)
These things may have naval analogs (galleons, triremes, U-boots, etc)
- You need to build a campus for a historical university to extract those archeology sites
- Museums for all the stuff
- Unique buildings: war memorial, tank museum (with some working tanks), maybe some place for historical reconstruction
DLC 3. Let's say "Commerce"
What for: to add diversity to commercial zones, they're boring now!
- New kinds of commercial zoning: malls, food markets, waterfront restaurants on piles, craft foods and beer, gentrified districts
- Extreme activities: base/rope jumping, jeeping routes, paragliding sites, cross-country cycling, etc
- Gas stations, charging stations for electro cars
- Car showrooms
- PARKING LOTS (including underground + multi-level)
- Markets and bazaars (e.g. Chinese, Eastern, etc)
- Maybe some walls and sites for street art
Thank you for your attention and have a good day!