We have become so accustomed to seeing three-dimensional worlds realised on our screens that it is tempting to think that the problem has, effectively, been solved. All there is left for videogame environments in a technical sense is just more detail and better lighting. But there is still a common failing of videogame representation that threatens to ruin my absorption every time I notice it. It’s this: even today, a lot of gameworlds don’t seem solid. And if the illusion of solidity fails, I’m reminded that I’m just soaring through an insubstantial field of maths and pixels. A game such as Rez actually wants to induce such constructively alienating delirium, but in other genres this feeling is akin to a kind of cognitive seasickness.

Take Virtua Fighter 4, for instance. There I am, gratified at a good representation of a Shaolin fighting style (for once), enjoying the excellent training mode, teaching my AI student in an amusingly sadistic fashion. Now, if I could just make him paint my fence and wax my car . . . Then it hits me, and my heart sinks: like every 3D fighting game before it, VF4 suffers from Slippy Feet Syndrome. These martial artists have no relationship with the ground. It’s not just an unrealistically friction-free relationship: it’s a bizarre lack of communication between the soles of the feet and the earth. Shoes slip randomly in any direction for a couple of inches and then come to an instantaneous stop. It’s as if the fighters have been badly bluescreened into a digital environment that is suffering a series of tiny earthquakes. The illusion of solidity, of contact between physical surfaces, breaks down.

Once you first notice it, Slippy Feet Syndrome is everywhere: more or less every modern third-person action game or FPS has it. And many driving games partake of the disease, in the form of Slippy Wheel Syndrome, when the tyres seem to be floating just above the tarmac. It is most noticeable in beat-’em-ups, however, because we enjoy a consistently close-up view of the characters. It’s there in Dead or Alive 3, too, which makes me wonder whether developers might hold back some of the processing surplus that is currently being spent on drawing pretty snowflakes to make sure their fighters are actually standing on something.

Like other forms of physical incoherence, SFS does not depend purely on visual cues: it can be ameliorated or worsened by information offered to the other senses. Despite its name, MGS2 is not irreproachably solid, because the character under your control suffers from slippy feet, yet that flaw is at least made palatable by the variety of foot-ground interfaces on offer. Slipping on birdshit, splashing through puddles, or clanking unstealthily over grates provides audiovisual feedback that provides a much richer illusion of surface-to-surface interaction than do most games.

I’m picking on Slippy Feet Syndrome because it’s a good example of how an apparently microscopic flaw can threaten to undermine so much creative and technical work in other aspects of a game. For the unfair truth is that as the worlds that videogame designers create become ever more complex and naturalistic, they can be ruined by ever smaller flaws, ever tinier holes in the logical fabric of the game universe. The world of, say, Gradius Advance is rock solid because it only has to process information in one plane, but adding a third dimension cubes the difficulty.

And if unnatural small movements of the pedal extremities can be annoying, what is there to say about larger breakdowns of solidity? The feet are one thing in beat-’em-ups, but if that rankles, you’d better cover your eyes when a fighter gets to grappling. Whether it’s Tekken, VF or DOA, grabs and throws simply look risible close-up because the bodies do not intertwine with the slap and heft of real flesh. Doubtless this is a difficult technical problem, as changes in the stance or orientation of the opponent in real life require a corresponding change in the movements for any particular throwing technique, and so a different animation in the game. Never mind, say the developers, here’s a rainstorm or a flock of birds to distract you.

Then there are the really epic breakdowns of solidity, where the whole world rips apart as if it were made of digital tissue paper. WipEout Fusion, take a bow: rockets and grenades don’t trouble the track, yet your ship can actually fall through it if shunted in the right way. That should never, ever happen. Because it’s one thing to want surfaces (as in feet and ground) to interact reliably, but I also want to be confident that the surface itself (the track) is physically solid and has depth. For all its flaws, Red Faction represented a step in the right direction in this respect: blowing chunks out of a cave wall with the rocket launcher still made smoking holes even if it wasn’t a specially designed destructible hotspot; and this worked to convince the player that he really was roaming below miles of igneous solidity, rather than encased in a two-dimensional, rock-textured shell with nothing but code-free void beyond.

Meanwhile, in the wider game world, solidity still seems at a premium. Really rough collision detection, of the sort that used to let Lara Croft get her arm stuck in a door, is less common these days, but even now most games will at one time or another simply let you walk through an enemy. The cunning Ico seems to play with this problem by remaining deliberately ontologically undecided as to the physical status of its shadow monsters. You can walk through them, but they can hit you, and if you swing a wooden stick at them they fall apart.

The fact remains that too many modern games just don’t feel as solid as even 3D Ant Attack or Knight Lore did. And if developers keep privileging fancy visual effects over tackling this problem seriously, then the realism so many of them seem to crave will never arrive.