Agoraphobia is bad enough. But it’s even worse when you’re saddled with this affliction — such a fear of open spaces that you literally never leave the house — and home is a gloomy and dilapidated indoor swimming pool run by your delusional and domineering blind father and a mother who charges only buttons as admission. Yet, throw in a scheming older brother, who wants only to have the creaky building demolished to make way for a housing development, and Eva (Chulpan Hamatova), a flirtatious pixie with an agenda of her own, and Anton’s (Denis Lavant) life is anything but dull. It’s an old cliche that there are only about half a dozen original stories and that we’ve simply been telling and re-telling them in a seemingly never-ending variety of ways. Certainly, everyone from Frank Capra (“It’s A Wonderful Life”) to Savage Steve Holland (“One Crazy Summer”) has spun their version of the “Save the fill-in-the-blank” story. Yet, I’d wager that no one has done so in as ambitious and unique a way as this brilliantly eccentric mess. Largely shot in an abandoned swimming pool in Sofia, Bulgaria using an ancient Arri and old-style carbon arc lamps, Veit Helmer’s “Tuvalu” — the name refers to an island in the South Pacific to which Anton and Eva desire to escape — is a wildly uneven, but visually spectacular film. Helmer has cast each scene, originally shot in black and white, in a different monochromatic tint, depending on its location. (Picture the rock score re-release of “Metropolis.”) Extremely ambitious and vaguely depressing, “Tuvalu” moves altogether too slowly for its own good. American audiences will have a difficult time adjusting to what is essentially a quirky silent film full of overwrought and bizarre characters. For those who do manage to stick with it and absorb what’s on screen in the same way that one would eventually absorb a new language, “Tuvalu” is ultimately a rewarding — if weird — experience. It’s just too bad that it takes so long to get there.