tabletoppingboardgames 
So… remember when building cities under the sea already felt like a lot to manage? Yeah, now we’re adding data to that mix.
In Underwater Cities, humanity has already moved below the surface, building these connected networks of domes, tunnels, and production systems just to keep things running. It’s not exactly relaxing. You’re constantly trying to balance resources, keep your cities fed, and make sure everything is connected properly. One weak link and your whole plan starts wobbling.
Data Era, the second expansion, doesn’t change that core idea. It just adds more on top of it. A new resource called data discs, some new buildings, more cards, and a few extra systems. Nothing that forces you to relearn the game, but enough that you’ll notice it almost immediately. I guess the real question is not whether it works, but whether you actually want that extra layer on top of a game that already asks quite a lot from you.
👥 1-4 players, ages 14+
⌛ Playing time: 80-150 minutes
📝 Designer: Vladimír Suchý
🎨 Artwork: Milan Vavroň
🏢 Publisher: Delicious Games (review copy provided)
Base Game Overview
If you haven’t played the base game in a while, quick refresher. You’re building an underwater network made up of cities, tunnels, and buildings, and everything needs to connect. If it doesn’t, it just sits there doing nothing, which feels about as useful as opening a restaurant where nobody can reach it.
Each turn, you pick an action and play a card. If the colors match, you get both effects. If they don’t, you still get the action, but the card doesn’t do anything. That simple system is where most of your decisions come from. You’re constantly trying to line things up, and honestly, it doesn’t always happen. When it does, it feels great. When it doesn’t, it can feel like you’re just patching things together and hoping for the best.
Production phases keep everything moving. Your network generates resources, your cities need food, and everything only works if it’s properly connected. It’s a fairly clean system, but there’s a lot going on once you’re in it.
Gameplay Overview
So what does Data Era actually add? The main thing is data discs, a new resource that works a bit differently from the others. You can split them into halves whenever you want, which already makes them more flexible than most resources in the game.
At first glance, it doesn’t seem like a big deal, but it changes how your turns play out. You can spend data discs to take one extra action during your turn. Just one, but that one action can make a big difference. You might draw extra cards, swap resources, build at a useful moment, or play an additional card to extend what you’re doing.
It doesn’t turn the game into something loose or easy, but it gives you a bit more room to work with when things don’t line up perfectly. That’s probably the biggest change you feel while playing.
On top of that, you get data centers, a new type of building. They cost a data disc to build and, if they’re connected, they generate data discs during production. Upgrading them also gives you credits, so they tie directly into both your economy and your options. They don’t feel like a side system. They’re part of almost everything you’re doing.
Then there are data cities, the blue domes. They follow the same placement rules as other cities but require a mix of resources, including a data disc. They also connect to a new scoring approach that rewards complete sets of buildings across your network. So instead of focusing too heavily on one type of building, the game gives you more reason to develop cities more evenly.
You also get more cards, assistants, and tiles, which mostly add variety rather than changing how the game works. It’s a solid amount of content, but the real impact comes from how the new resource ties everything together.
Artwork, Components, and Visual Design
If you know the base game, nothing here will surprise you. The expansion sticks to the same underwater look, with lots of blues and glowing highlights. It still looks good on the table, especially once your network starts spreading out across the board.
The blue domes stand out nicely and make it easy to spot the new cities. Data discs are clear and easy to use, and the different values are easy to tell apart during play. The upgraded building pieces are actually one of the more practical additions. Stacking buildings in the base game could be a bit awkward, so having proper upgraded pieces just makes things easier to manage.
Our Experience
Coming back to Underwater Cities with this expansion felt a bit like rediscovering something we already liked a lot. It’s one of those games that doesn’t always hit the table regularly, but when it does, you immediately remember why it works so well.
The first thing we noticed is that it doesn’t feel like something extra on top of the game, it just feels like part of it. The core of the game is exactly the same. You’re still managing your hand, picking actions, building your network, and planning for production. That part never changes, and that’s a good thing.
What does change is how much room you have inside that structure. The data discs give you more ways to deal with situations where your hand and the board don’t line up. You’re less likely to feel stuck, and more likely to find a way to make your turn useful. That doesn’t make the game easier, but it does make it feel smoother and more forgiving in the right moments.
We also noticed that it changes how you approach your network. There’s more reason to think about building complete cities and connecting everything in a way that supports both production and scoring. It’s not just about expanding anymore, it’s about how everything works together.
At the same time, it does add quite a bit of weight. There’s more to keep track of, more to plan around, and more to think about each turn. For groups that already take their time, this will probably make the game even longer. That’s not necessarily a bad thing, but it’s something to be aware of.
What we liked most is that the new ideas don’t feel separate. Everything ties back into the main system. Data discs are used for extra actions, for building, and for scoring, so they become part of how the game works rather than something extra you have to remember.
Our Thoughts
We think Data Era works best when you see it as a refinement rather than a big change. It doesn’t try to replace what makes Underwater Cities interesting. It just gives you more ways to work within that system.
The strongest part of the expansion is how the data discs affect decision-making. They don’t just give you more resources, they change how you think about your turns. You’re not only reacting to your hand and the board, you’re also thinking about how to extend or adjust what you’re doing. That gives you a bit more to work with, without changing what already works.
We also really like how the expansion connects different parts of the game more closely. Data centers, city development, and scoring all feed into each other, which makes your overall plan feel more connected. You’re not just building things for points, you’re building a system that supports itself.
At the same time, it does push the game further into heavier territory. There’s more going on, and the difference between a decent turn and a strong one depends even more on planning ahead. That’s great if you enjoy that level of depth, but it also means the game asks more from you.
Another thing worth mentioning is that the expansion becomes part of the core experience once you add it. It doesn’t feel optional in the way some expansions do. That’s not a negative for us, but it does mean you’re committing to a fuller version of the game.
Overall, we really like what it adds. It respects the base game, builds on it in a meaningful way, and adds more room for players to shape how their turns play out. It won’t change anyone’s mind if they didn’t like the base game, but if you already enjoy it, this feels like a very natural next step.
Final Thoughts
If you already enjoy Underwater Cities, this expansion is easy to recommend. It adds more options, more ways to plan your turns, and more ways to connect different parts of your network, without losing what makes the game work.
It does make the game heavier, and it won’t speed anything up, so it’s probably not something to introduce right away to new players. But if you’ve played the base game a few times and want more from it, this feels like a really good addition.
For us, it’s one of those expansions that doesn’t try to impress with big changes, but instead makes the game feel better the more you play it. And honestly, that’s exactly what we want from something like this.
📝 We received a copy of the game from Delicious Games.
