Shocked to realize it has been a full year since I last posted in this thread. Continuing to muck around in this genre, and recently bought “Theme Aquarium” on PS1.
If you read one of the few articles written in English about the game, you will learn about how it was essentially an outsourced project that was given the “theme” label to boost name recognition.
Really, though, it has a lot of the same bones as Theme Hospital or Theme Park in terms of presentation and basic operation. The visuals are nice and there is quite a high number of different items to place. Given that I was mostly interested in the latest Animal Crossing just for the aquarium, and in FF14 my main disappointment with fishing was the limited nature of aquarium-displayable fish, this game scratches some itch.
Typical interface for placing objects/tanks, but the level of micromanagement (at least initially) is interestingly high. Unlike TH or TP, placing an ‘attraction’ (a tank with fish in this case) isn’t just a set and go process. Of course salt and fresh water settings are to be considered, but each fish has preferred temperatures, and reasonably so, preferred tank-mates. The information for this is presented in an in-game ‘encyclopedia’, which you have to go and access.


Without looking it up, you are basically playing blind as to what the correct settings are, and will likely just kill your fish. This initial setup, for me at least, puts me in some mindset of taking the whole affair seriously, and just slowing down and paying attention. A valuable thing to be encouraged to do by a game, even if there is friction introduced.
Each screen transition takes about 3-5 seconds to load, which again just slows you down. In order to see the specific needs of your fish, you need to zoom in on the tank and enter preview mode, which gives you a nice animated scene with basic sprites moving around.

Fish have a bunch of different emotes, and there really doesn’t seem to be a way to see this information without zooming in to this tank view. You can see general health/hunger, but not whether they feel crowded or too cold or what.
When selecting fish to purchase, you can first buy them from suppliers, who group the fish by region (NA, Japan, Great Barrier Reef, etc), but only have a limited selection depending on the game mode. The other novel element of this game is the expeditions - you can choose to send (almost any of) your staff members out on trips to try to gather / catch fish on a world map. You do this by first rolling some handful of dice to determine the number of moves you can make for scooting your little boat along the world map, and you might face random events like storms that throw your expedition off. The video below shows the last move of coming back to the aquarium and unloading the acquired fish.
I don’t yet know much about getting fish this way, but each staff member seems to have different skills that are associated with what they can acquire as well as their expertise as a caretaker.

You also can do a fish exchange via memory card with another save, so if your friend has caught a particular fish you want, you could trade. This feels pretty similar to Jurrasic Park - Park Builder on GBA, with the DNA system.
Finally, there is pocketstation support, which involves being able to train your dolphin (which appears to be the kind of crowning achievement of an aquarium). The dolphin show is showcased on the game case for its polygonal graphics, and it looks like you can train your dolphin on-the-go with the pocketstation, and do things like race an opponent dolphin.
If you’re curious and want to play in English, it appears it came out as “Aquarium” on PC in Europe, likely can be found somewhere online. No idea what changes they may have made between the versions, but I was pretty stoked about this find. While not maybe as prestigious as TH, as a concept, it really works as a Theme game.