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Imagine “Alien” told in the style of “The Blair Witch Project”—in mock “found footage” style with very little budget—and you’ll have some idea of what “Apollo 18” aspires to it. Unfortunately, even if you’re intrigued by the idea, the finished product is too flat and tedious to be much more than a footnote to the stable of pictures that have tried to emulate the threadbare pseudo-realism of “Project,” a few successfully (“Paranormal Activity”) but most not (“The Last Exorcism”).

The historical conceit—another in the “let’s rewrite history” splurge of the year—is that though the Apollo manned missions were supposed to have ended with No. 17, there was actually another secret lunar landing in 1972. An extremely hush-hush endeavor, it involved the spaceship Freedom and landing craft Liberty. Aboard were three astronauts: Walker (Lloyd Owen) and Anderson (Warren Christie), who actually descend to the surface, and Grey (Ryan Robbins), who remains in orbit while the module lands. The purpose of the flight was supposedly to install radar implants as part of a missile-defense system.

Once on the moon, however, Walker and Anderson discover an abandoned Russian landing craft, and eventually the body of a cosmonaut as well. Worse still, Walker discovers an alien life form, which burrows into his abdomen and infects him before Anderson removes it in a scene that’s a pale reflection of the famous chest-bursting in “Alien.” Of course it turns out that the mission was actually a Defense Department operation to get intelligence on the destructive creatures, in which the three astronauts were expendable pawns. And the long-suppressed footage of the whole dirty business has been unearthed and posted, according to the opening title box, on a Wikileaks-type website devoted to “lunar truth.”

The suggestion that the government conspired to dupe the public about space missions is nothing new to cinema—remember “Capricorn One”? But while that Peter Hyams picture had characters you could care about and some clever dialogue, the three guys here are dull as dishwater (despite an attempt to give them personality with some home movie excerpts and introductory interviews) and the writing utterly banal. As for the creatures, they’re revealed to be embedded in lunar rocks, of the sort that are regularly handed out as souvenirs back on earth (an echo of that old “Outer Limits” episode “Corpus Earthling,” and when they hatch the little we’re shown of them suggests that they resemble the nasty insect-like beasties of another “Outer Limits” show, “The Zanti Misfits”).

That leaves only the look of “Apollo 18” to pique one’s interest, and though the makers are adept in melding newly-shot material with what appears to be archival and news film, and create an effective lunar landscape, the stream of jerky, fuzzy, static-riddled and otherwise distressed visuals gets exhausting and rather boring after awhile. It’s a trick that’s gone stale, and “Apollo 18” doesn’t freshen it up very successfully.

And “Paranormal Activity 3” is on the horizon.