This is an OVA based on the Deep-Blue series game 'Tristia of the Deep-Blue Sea'. I'm frankly baffled as to how such an obscure series managed to get any animation at all but the mid-2000s were a strange time. I have played some of the games so I can comment that this OVA does a pretty good job at conveying the basic jist and tone of the game, but it's definitely not a stellar anime overall. It really depends on whether your love of mid-2000s anime tropes dialed up to 11 in some bizarre comedy of a mecha anime fights through. Deep-Blue is a bitof a weird mix between a visual novel and a city-building sim with mechas bolted on, it's sortof like if an Atelier game was set in a Aria-esque universe which i really dig, it's a shame that style of world fell out of fashion in the 2010s.

The animation is quite good, there is a bit of visual flair going on but this does obviously come off as a budget production. It definitely isn't anywhere near as bad as some other stuff from this generation like the IDEA Factory crap. I trawl through alot of trashy OVAs from this period and I can honestly say that this probably has some of the best animation i've seen in all of them all things considered. One thing that's really standout are the colours, they're alot more saturated than most anime and make it look alot bolder, and the way that they adapted them in various lighting conditions was really well-done. Especially in darker scenes where they still keep most of the colour which I haven't really seen done before and was quite memorable.

The voice acting is pretty decent, though nothing standout. I don't know for sure whether the same VAs reprised their roles for this animation but they do sound pretty alike regardless. But fun fact: there is a Russian dub floating around on the internet and it is actually quite good. If you can track it down it definitely adds a little bit if you're getting bored. The music is also really really good, as alot of the tracks are taken from the game verbatim.

I think the worst part is the story and the pacing, it feels like they tried to balance too many storylines for 2 episodes, as well as have some character development and mecha fights. If this was maybe 4 episodes long and a bit more segmented that wouldn't be so bad but it can't be helped given there's only 60 minutes. I think it definitely makes alot more sense if you have played the game, which most people watching likely haven't since none of them have been released or localised outside of Japan until recently. Kogado as a whole definitely caters to a more dedicated customer base (with alot of fandiscs and merch) so the fact this OVA assumes some knowledge makes a bit more sense.

One of the things I like the most that might be lost on alot of people is that all of the characters are named after aircraft, Nanoka is named after the Sukhoi SU-37 Flanker, and the villainess is named directly after the Panavia Tornado multi-role aircraft. I still haven't really been able to find a solid reason as to why this is but I can only assume it's just mid-2000s quirks showing up again. You really just couldn't have an anime like this again.

If you were interested in following the series a bit further there were the following games:
* Tristia of the Deep-Blue Sea - PS2, PSP, PC
* Neosphere of the Deep-Blue Sky - PS2, PSP, PC
* Amaneka of the Dawn and the Deep-Blue Titan - X360, PSP, PC
* Silver Cal and the Queen of the Deep-Blue Sky - PSP, PC

The series does seem to be on hiatus but Tristia is getting a localisation and remake now for Steam luckily.
https://store.steampowered.com/app/2244160/Tristialegacy/