Armies Of Exigo. Publisher: Electronic Arts. Format: PC. Price: £29.99. Family friendly? Teenagers only.

WORLDS collide in Armies of Exigo, a fantasy real time strategy (RTS) game where the boundaries of the battlefield are broken and war is waged both above and below the ground.

On paper, it sounds like a thousand other strategy fests: elves, beasts, knights, and creatures of the darkness fight for supremacy in an epic fantasy world. They mine planetary resources, build defences and refine their weapons. Just like every RTS since Dune II ten years ago.

The plot is the usual sub-Tolkein fantasy nonsense: in the world of Exigo, where peace and prosperity have reigned for years, the empires of man and beast face their greatest threat yet.

A sinister force known as The Fallen has woken to strike where the inhabitants of this world least expect - from underground.

Users will take control of massive armies, wage wars in the forests and river valleys of the surface, then descend into the caverns and catacombs of the underworld to face off against the dark evil.

The catacombs aren't just places for The Fallen to run and hide when things get rough - they're a totally new level of the game, and players are expected to do battle on both at the same time.

You switch levels by simply pressing the TAB key, and flicking across the worlds is often the key to victory.

In some cases, you will be required to march your armies between the two levels - stepping into the unknown. You can also set up ambushes by stationing men at the entrance and waiting for your foes to march through.

The idea of fighting a battle on multiple levels hasn't been tried before and it works really well. There's no chance to relax; if you aren't fighting above ground, you'll be fending off the hordes in the subterranean realm. Thankfully, you also get a picture-in-picture facility to monitor both at once.

Graphically, RTS games have always looked good (even when Command and Conquer required nothing more than a 486 PC and 4MB RAM) but Armies takes things to the next level. Everything is fully modelled in three dimensions; your armies can use the terrain to their advantage, setting up choke points and hiding behind rocks or broken ruins.

The resource mix is finely balanced. The Empire has straightforward infantry, archers and swordsman. The Beasts use the supernatural denizens of Exigo like giants, goblins and harpies, to do their bidding. As the true bad guys, The Fallen can call upon the demons of hell to kick your butt. The Fallen armies harvest the souls of the dead and become more powerful after every battle they survive.

The explosions and spell effects are tremendous. Given so many different vehicles and soldiers, when most of them are on screen, your PC monitor becomes a veritable pyrotechnic feast for the eyes.

Armies also throws in the usual multiplayer modes (capture the flag, king of the hill, melee etc) for gamers who like to test their strategies against human opponents.

With its carefully crafted gameplay, beautiful looks and longevity, Armies of Exigo deserves a place in any strategist's library.

Alexander. Publisher: Ubisoft. Format: PC. Price: £29.99. Family friendly? Over 12s.

HERE'S another real time strategy fest - only one based on the massive movie flop Alexander.

At least that spares Ubisoft of the need to craft ridiculously expensive cut scenes linking the game together - Oliver Stone had already done it.

Here you have 15 missions that take in all of Alexander's career from his early days quelling revolting peasants to his return to Babylon.

Once you've completed the Alexander campaign, you'll unlock three new levels where you get to pit your strategies against Alexander himself as the head of the Persians, Indians or Egyptians. Each of these three consists of several additional missions. As well as these four campaigns, the game also includes a handful of single, scripted missions, a skirmish mode and multiplayer.

The standard of gameplay is variable, but the missions are fun for a while and the graphics look nice. One major criticism, however, is the way large-scale battles can degenerate into a hard-to-fathom melee within seconds.

Sometimes it was hard to feel as though I was in charge on the battlefield.

Unfortunately, this is RTS-lite. Seasoned campaigners will breeze through Alexander without breaking into a sweat.