Topping the brilliant Ratchet & Clank: A Crack In Time was always going to be a challenge for Insomniac Games.

The developer's previous entry in its highly acclaimed platforming franchise neared perfection in terms of level variety, design, and combat. Short of sprucing up the graphics and adding more of the same, it's hard to see where else Insomniac could take the Ratchet & Clank formula. And so All 4 One is wholly familiar, yet blaringly unique at the same time.

The twist — as you're no doubt already aware — is that All 4 One is a co-operative title designed for four-players. While the core Ratchet & Clank staples are still apparent — players can double jump, smash up crates for bolts and fire extraordinary weapons — the moment-to-moment mechanics are centred around working closely with your team.

There are four characters up for selection: Ratchet, Clank, Captain Qwark and Dr. Nefarious. Naturally we spent our demo playing as Qwark. The first level we tested out was set in an aerial city not too dissimilar from the neon futuristic environments we've seen in Ratchet games before. The level felt like a tutorial stage, as we spent our opening fifteen minutes of the game smashing up crates (which, in fairness, never gets old) and leaping across hazardous chasms. The level felt a bit drawn out and basic — we understand its intention was to introduce the game's mechanics, but being already well versed in the Ratchet & Clank universe led to some tedium.

Thankfully not everything in All 4 One is familiar. Players now have access to a new vacuum weapon which can be used to sweep up co-operative partners and launch them over distant gaps. Players can also grab onto their partner at any time by holding the Triangle button, creating a leash and pulling everyone back together.

As our demo transisted into a second level — set in a more tropical, desert environment — Insomniac started to get more creative with the mechanics. A boss-fight, for example, saw us using the vacuum weapon in combination with our partner to break a robotic enemy's shield and open him up to fire-power.

The combat itself feels a bit drab. Perhaps it was a consequence of our short demo time, but we had issues with the game's automatic lock-on. In addition, the gunplay didn't feel its usual satisfying self. Enemies took numerous hits to drop, and the guns themselves were surprisingly light on ammo. Perhaps we missed a key piece of exposition during our time with the game's tutorial stage, but this was obviously disappointing. Part of Ratchet & Clank's appeal is feeling ridiculously overpowered, and while the weapons we used looked enormous, they barely registered a hit on our opponent's life bar.

It was the non-combat elements that really got us excited about what we saw of All 4 One. For example, one mission put us in a taxi and challenged us to work as a team to steer the vehicle by altering its weight. The mini-game itself was simple — avoid the oncoming traffic — but working as a team to rebalance the car required perseverance and communication.

It's disappointing then that the bread-and-butter of Ratchet & Clank: All 4 One feels slightly janky compared to its co-operative diversions, but we still have hope that this was a consequence of our sporadic demonstration time. If Insomniac can tighten up the gunplay then All 4 One's destined to sap a lot of our time in both local and online co-op.

Ratchet & Clank: All 4 One releases exclusively on PlayStation 3 in October.