What makes a VR version of a familiar genre worth playing?

For me, Virtual Reality is an opportunity to escape to new worlds. I don't just mean touring through clusters of supernova nebulae while sprawled on my bed, or wandering about the Medina of 12th Century Rabat during The Bachelor's commercial break. I mean playing new types of games, previously unimagined.

I'm not much interested in re-visiting the same experiences I can get on a PC, a console or even a handheld device.

Like all previous game platforms, VR is going to host plenty of attempts to cash in on well worn genres. Because its potential for innovation is so far beyond any of the hardware launches we've seen before, this offers stark, polar potentialities. At one end of the spectrum, innovative re-imaginings of things we thought were all played out, and on the other, a lot of pointless ports that make very little sense as VR games.

To be honest, I greeted the opportunity to play a tower defense game on Oculus Rift with roughly the same enthusiasm appropriate to attending a garden center winter sale. So, it came as something of a surprise that Defense Grid 2 VR on Oculus Rift is a way more impressive experience than I'd anticipated.

A decade ago, tower defense games were all the rage. They require the player to observe marching waves of enemies (usually aliens or monsters), and to place artillery and ordnance along the baddies' path. They are compelling puzzles, for a while. But I haven't played one in a long time. At advanced levels, they can start to feel less like a compelling brain-teaser and more like a dreary Sunday chore.

Really, how long can anyone sustain a passionate relationship with lining up gun turrets in wormy formations, while watching resource upgrade buckets slowly fill up?

But tower defense still has its adherents. Among aficionados, Defense Grid 2 is viewed as one of the best. Released in 2014 for PC, PlayStation 4 and Xbox One, it's set in a neon space world, serving up smartly designed levels, satisfying squishy aliens and the ability to take one step back if you make a tactical error.

Defense Grid 2 takes the core genre and represents it in a flashy and highly competent package with some surprisingly fresh additions to the basic formula. It's developed by Hidden Path, a development team with a solid reputation. They also did an excellent job refreshing Counter-Strike with CS:GO.

So what makes a VR version of a familiar genre actually worth playing?

In this case, the formula itself is unchanged, otherwise it wouldn't be a tower defense game. Instead of using a mouse to move about the game, the player looks at the relevant piece and presses a controller button to effect movement and change. But the platform is being used in ways that seem to enhance the experience.

VR is about perspective, about seeing the world as if the player is a part of the world. Tower defense games are essentially board games, semi-static simulations of the world that are viewed from above. Hidden Path has sought to marry those things to create something fresh.

First, the game delivers a stark feeling of submersion by creating massive depth. One level is set on an asteroid, with the player hovering above. Beneath the asteroid, the void of space is dotted with planets. It's not a terribly sophisticated trick, but Hidden Path has clearly grasped that, at least in its early days, VR's appeal is going to be in seeing the world differently.

Second, the player is able to lean right over the board, in order to inspect angles of approach and corners that the enemies might use to their advantage. Indeed, the board has been designed to offer up secret bonuses that are only won by really moving around and looking at the game from different angles. Crevices and fissures hide bonuses.

Third, the player needs to look around on a vertical axis in order to take in potential platforms at the outer reaches of the board. These kinetic terraces rise and fall, but need to be grabbed and used to extend the player's field of annihilation.

Finally, the player can decide to be transported into the perspective of a tower. This gives the added pleasure of witnessing the destruction of enemies at one's feet. I can't work out if this is a gimmick that will grow tedious after a few plays or if it might have some tactical usefulness. It seems to me that being able to see the battle from any perspective at any time must carry utility.

If nothing else, it's fun to enjoy the satisfaction of a well-placed gun turret first-hand.

Taken separately, none of these additions are especially profound, but as a collection, they add up to a new way of looking at a tired genre in VR. No doubt, we will see some lazy implementations of familiar game styles in the months ahead, as VR units begin to proliferate. We may also see some well-meaning but ultimately flawed executions. But, based on an hour's play, I'd say that Defense Grid 2 VR is a strong start.