Sub Rebellion (PS2)

Even moreso than tanks, submarines are pretty under-represented when it comes to videogames. The only really well-known sub game I can think of is the classic arcade shooter In The Hunt, which, coincidentally, was created by Irem, in their fondly-remembered "dirty-looking pixelart" period, while Sub Rebellion was also made by Irem in their later, more tragic "weird experimental PS2 games" period. (Tragic because it was the last stage of their existence as a games company, pretty much.)

So, Sub Rebellion, then. It's set in a post-apocalyptic future (like almost every Irem game, come to think of it), in which the world has flooded, and humanity survives in underwater cities, most of which are ruled with an iron fist by an evil empire. You play as a submarine-piloting mercenary tasked with helping the resistance save humankind, and if you have time, also finding lost artifacts of an earlier age, which can be used to develop new technology to upgrade your sub. Is it a requisite that every underwater PS2 game has to have you looking for sunken treasure?

The missions are pretty much as you'd expect: find the thing (or things) and blow it (or them) up. Then, without fail, a boss will show up, and you blow them up, too. And while you're at it, keep pinging your radar to find buried artifacts, which are excavated by blowing up rocks and dirt. Though the controls use every button on the PS2 controller, plus both analogue sticks, they're very easy to get ahold of, and it won't belong before you're swoocing through the depths like a big clunky metal mermaid. You have two main weapons to facilitate your blowing up of objects: a machine gun, fired by tapping the fire button, and lock-on torpedos, targeted by holding the fire button, and fired by letting go.

Sometimes, you'll also have to surface and sail around shooting helicopters and gun turrets and the like, which is actually a lot harder, since your enemies can move around and dodge your attacks in 3D, but you're mostly confined to 2D movement in this state (though you could go the slightly unweildy route of dodging surface attacks by submerging when they get too close, I guess?), and to make things worse, you can still be fired upon by sub below you while you're surfaced, which is a bit unfair.

Sub Rebellion is a pretty great game, to be honest, though it can be frustratingly difficult, especially when you die right at the end of a mission you've spent 10-20 minutes playing through. I can only assume the reason it never got anyone's attention is it's generic-sounding name, and generic-looking boxart, and for once, the western publisher's can't take the blame, since it had the equally dull title "U:Underwater Unit" in Japan. Anyway, you can pick up a copy of this game dirt cheap, and it's definitely worth doing that.