C.S. Lewis’ series of Narnia books, published during the early 1950s, are deservedly classic, beloved by many who encountered them at a young age. But there are several reasons why they haven’t been filmed very successfully before now. One, of course, is that they’re filled with fantastical elements that, until the advent of computer-generated effects, were difficult, if not impossible, to pull off on screen. That certainly explains why the late eighties BBC television versions of three of them (including “The Lion, the Witch and the Wardrobe”), which were made fairly imaginatively but on very limited budgets, could be considered at best stopgaps. (There was also a 10-part TV series of “The Lion” in 1967, as well as an animated version of it in 1979, neither of which is either widely available or highly regarded.) But they’re also filled with the sort of Christian messages—“The Lion,” after all, is basically a retelling of the salvation story–that can be instructive and appealing on the printed page but can easily turn heavy-handed in a film adaptation. (Even the harrowing of hell, which is after all an addition to the Scriptural story of the resurrection, is included.)

This opulent version of “The Lion,” the first of the seven “chronicles” written (although in chronological narrative terms, actually the second) easily overcomes the first difficulty: the visual effects are very good, and seamlessly integrated into the live action, even when it means joining the top half of an actor like James McAvoy (who plays the lovable faun Mr. Tumnus) with the legs of a goat; the various talking animals–not only the lion but the beaver, the horses, the wolves and the fox–are splendidly rendered, too. The visual effects team led by Dean Wright, visual concept designer Richard Taylor, and creature co-creators Howard Berger and Gregory Nicotero are to be congratulated.

But one really takes that for granted nowadays, even in the fantasy-based TV miniseries produced by the Halmi organization. Where this movie proves a disappointment is on the narrative side. First, it doesn’t handle the second big potential problem–how to treat the Christian elements embedded in the story–very skillfully. Simply put, it highlights them in ways that seem ham-fisted beside Lewis’ subtle handling, something that’s most apparent in the “Christ-like” lion Aslan’s scene of self-sacrifice and resurrection, which is here played out very intensely. Maybe that’s inevitable when a book–even one of modest length like this one–is whittled down to screen size (at under 140 minutes, “The Lion” is still forty minutes shorter than the BBC telling). Or perhaps it was a conscious choice made in connection with the interests of Walden Media, which co-produced the picture with Disney, and with a view toward the marketing process that was eventually adopted, which has sought the support of church groups in giving the movie a big send-off. (If not for “The Passion,” after all, “The Lion” might never have seen the light of day.)

But there’s a larger narrative problem at work here. In being as true to Lewis as possible, the picture adopts a gentle, almost lackadaisical gait; especially in the first hour or so, when the focus is on the removal of the four Pevensie children from blitz-threatened London to the rural estate of Professor Kirke prior to their discovery of the magic wardrobe that takes them to wintry Narnia, the mood is that of a shambling British period piece, pleasant enough in its own way but compared to the more bustling, energized worlds of the franchise epics in whose footsteps it obviously hopes to follow, “Harry Potter” and “The Lord of the Rings,” pretty pallid. Even when the action moves into Narnia, the pacing by today’s standard is slow, and the level of excitement never reaches a high pitch, even during the big battle scenes that represent Armageddon at the close. And though character like Tumnus and the Beavers (voiced by Ray Winstone and Dawn French) are delightful in many respects, their presence can’t escape the whiff of Disneyfication, reminding us of the studio’s long history of anthropomorphizing animal characters in their feature cartoons. And quite honestly not much can be done with Aslan, the rightful ruler of Narnia and leader of the rebellion against the usurping White Witch. The lion’s lines are intoned with solemnity by Liam Neeson, but the beast is so high-minded and even-tempered (despite a few growls and a rather summary treatment of the witch at the close) that he comes across as a sturdy but rather tedious fellow. There’s a bit too much piety at work here; being Christlike doesn’t mean being recessive and slightly dull.

Most of the human performers fare better. Tilda Swinton exudes nastiness as the White Witch; when she bares her fangs, she doesn’t hold back or plant tongue in cheek–she plays it straight, and fearsomely. McAvoy makes an affecting Tumnus, and Jim Broadbent an appropriately eccentric Kirke. The four children are fine, too, even if they seem a bit held back by Andrew Adamson penchant for English understatement. Most importantly, Georgie Henley is a sweet, scene-stealing Lucy, and Skandar Keynes catches Edmund’s initial meanness and his ultimate conversion to heroism. William Moseley is a pleasant Peter, even though inevitably he’s over-parted when he must don knight’s garb and sword in the final act; and though Anna Popplewell has less to do than the others as Susan, she’s attractive and exuberant. And it’s certainly not their fault that the big throne room scene at the end, in which they’re feted for their triumph in restoring the Narnian spring, is entirely too reminiscent of the closing moments of the first “Star Wars” movie for comfort. On the technical side, special praise is due production designer Roger Ford, supervising art director Ian Gracie and his team, costumer Isis Mussenden and cinematographer Donald M. McAlpine. Harry Gregson-Williams’ score hits the right buttons without being especially memorable.

And that phrase might well be applied to the entire enterprise. As “The Lion, the Witch and the Wardrobe” comes to its rather stretched-out climax (or multiple climaxes), one is left with the gnawing suspicion that while it’s a decent adaptation that should satisfy fans of the books, it really belongs on the Hallmark Channel instead of the big screen. There’s an underlying blandness the picture never shakes.

My favorite Lewis book, incidentally, is “The Screwtape Letters,” but I certainly wouldn’t want to see somebody try to turn that into a movie. And despite the obvious sincerity and honest effort behind this initial installment of what’s clearly intended as the start of a “Narnia” franchise, I suspect it’s likely to remain an isolated effort. But admirers of the author can always return to the wonderful “Shadowlands”–still a deeply affecting film–for a first-rate biographical fix.