For no real reason, Makoto (if I remember correctly) from #ndt brought this up, and I had the irrepressible urge to play it. So I did. Do note that 90% of the stuff I’m about to say is mostly guesswork, with some crazy-ass romanization.
蒼海の皇女たち (Soukai no Oujotachi – Princesses of the Blue Waters) is set in a fictional world with two of its nations fighting each other for control of territory/resources/whatever (I can’t remember anymore) with you on the side of Nordenfeldt army. Apparently, the higher-ups decided to initiate the Mysteltine Strategy, where a submarine would be deployed against the enemy, supposedly to boost your nation’s army’s morale. Of course, this being an eroge, everyone but the captain is a woman. Playing as the captain, Aal Vanrieth, of the Uldiana, you are to guide a crew of 43 (women) to help your country win the war.
The game itself is pretty standard fare, for an eroge. Lots of talking, occasional decisions, and so on. However, the engine it runs on allows for some pretty neat stuff:
For example, there are cut-ins, which function almost like a second window. These cut-ins allow the player to see from two different viewpoints, which is kinda cool, if you like that.
There are probably other overlays too, such as this where the the name and rank of the girl you’re talking to appears. In this case, you’re talking to is First Lieutenant Stia Noil. She’s a senior officer and second-in-command (and obviously one of the main girls).
Not only that, but within the window, 3D Movies are overlaid too, mostly from a camera angle outside of the sub to show you what’s going on. In the videos here though, they merely show the sub traveling through the water, though I suspect that they’ll get to bombers dropping their payloads, destroyers laying depth charges, and of course, your sub taking out ships (but hopefully not the other way).
Anyway, it’s actually quite a chore to play because I use rikaichan and Wakan a whole, whole lot when it comes to translation, so my desktop looks something like this. However, I’ve never really tried my hand at playing eroge “raw”, so this could be a good learning experience.