As LucasArts’ admirably experimental hill ’em up nears release, it’s starting to look like a game that’s split straight down the middle, a tectonic clash of alluringly risky innovation and staggering, arthritic cliché. It seems that LucasArts is scared that an audience will find the terrain-deforming gameplay unpalatably cerebral unless it’s dressed up in a comfortingly apocalyptic familiarity: a mixture of shaven heads, gritty attitude and phonebook-thick armor that may turn into a devastatingly effective cloaking device when Fracture appears alongside a dozen other interchangeable epics at retail.

That would be a real tragedy, because Fracture isn’t a bad game by any yardstick – in fact, it often provides sparkling firefights and contains some clever level design. LucasArts’ most recent reveal – hands-on with the game’s Alcatraz Island tutorial – is, in part, a testament to Fracture’s ability to suck you in: we’d played through a hefty chunk before actual enemies had turned up, and we hadn’t even noticed they’d been away.

But Fracture was always meant to be far more than just solid entertainment: it was meant to dazzle and amaze, introducing terrain deformation as a new shooter standard to go alongside Halo’s rechargeable shield and two weapon slots (both of which Fracture cribs). The tutorial, however, gives worrying hints that, even this early on, cracks may be starting to show.

The central problem is also, somewhat disconcertingly, the game’s star: the ground-shifting arsenal, forever promising freeform fun but yet to convincingly deliver it. There may have been a miscalculation here: revolutionary weapons (Half-Life 2’s gravity gun comes instantly to mind) create astonishing possibilities because they are theoretically interesting in almost any context; weapons that allow you to alter the height of the ground have far more limited possibilities.

In short, Fracture presents you with a specific key, and then throws up endless locked doors, tailor-made to be opened by it. It’s no less ridiculous than if the game had given you a gun that fires brandy butter, before presenting you with a sequence of battlefields littered with thousands of ungarnished Christmas puddings. There are only so many situations you can face that just happen to require the floor to be at a slightly different height before the whole process starts to feel artificial.

More worryingly, when you deviate from the script, the game freezes you out. You can raise a hill to get over a specific pipe that’s blocking your way, but if you try hopping over the railing to the left instead, you bump into invisible walls. Equally, throw a tower-spawning Spike Grenade beneath a mission-critical crate, and Fracture renders it a surprise dud – flatly refusing to play along with your mischief and loft the crate out of reach.

Part of the problem is that using a tutorial as a demo is a bit like trying to sell someone a Ferrari by showing off how nice the ignition key is. Tutorials are, by their nature, the most formulaic and controlled aspect of a game, and linearity is to be expected. Gaping inconsistencies are not, however, and it’s hard to believe that Fracture won’t play the same tricks later on.

Watching a developer walk through part of the game’s desert-based middle act, these fears initially seem confirmed: the same fierce linearity and the same uninspiring objectives (there’s something depressing about being an earth-shifting supersoldier and finding yourself tasked with deactivating a couple of power generators). But things pick up with the arrival of a new weapon and a new enemy. The Ice Rifle is an inspired addition to the arsenal. Yang to the ground-flipping Entrencher’s yin, it allows you to temporarily freeze sections of earth, either to lock cover in place, or stop enemies from raising their own. Creepers, viciously deformed scorpions, are equally promising: burrowing underground, they force you to use tools imaginatively, raising the earth to avoid attack, or scooping it out from under them. Suddenly, Fracture has created a triumvirate of weapons, enemies and environments that spontaneously creates experimentation. Hopefully LucasArts has more like this up its sleeve.

Fracture remains a game you’ll want to love: at its best, it’s genuinely innovative, and at its worst it’s never less than heartfelt. There’s every chance that developer Day 1 could still do a Portal, mixing up simple components until they create exciting results; even without that, multiplayer will have to go very badly wrong to avoid being brilliant. The nagging feeling, however, is that in Fracture’s case being first with a new concept may not necessarily mean claiming the trophy; it would be far from impossible for a competitor to take these innovations and turn them into something that really comes to life. It’s sad to admit, but with Fracture still months away, the game we may really want is Fracture 2.