After becoming something of a cult classic on the PlayStation Network it was only a matter of time before somebody realised this would work even better on PSP. For those of you who haven’t played the PS3 version this is a tower defence game. You build defence towers out of trees, using a limited supply of money in order to defend your village’s twenty inhabitants from multiple waves of invaders.

The towers are designed to be effective for ground or air attacks with some of them spreading themselves thin to do both. There’s plenty to choose from if you can afford them. There are canons, freeze guns, Telsa (electricity spewing towers), mortars, flamethrowers, crossbows, anti-air guns, lasers and electric barriers.

The towers can be levelled up by standing in their vicinity or by spending gems on them. Money (used to buy towers) is dropped by defeated foes or found hidden in the trees. Gems are also dropped by enemies but much less frequently. Towers will also gain their own experience points while they notch up kills. It’s tough trying to balance using gems to upgrade your existing defences or saving up say 15 of them to unlock a new variety of tower. After a few waves, coins are in plentiful supply and you can sell unwanted towers if you need extra.

Waves of enemies include: lumbering stone golems, speedy giant spiders (aka you spidery bastards), bats, little furry things, flying little furry things and more. Some of them will arrive glowing, meaning they are immune to certain types of tower, so you’ll have to adapt your strategies.

After you’ve got the hang of things you should be able to get through the onslaught of enemy waves for a stage with only a few losses at your village. However, if you want to progress to the extensive areas of the island you will need to earn Rainbows. These can only be earned by clearing a stage without losing a single villager.

So if one bastard spider gets through on the 19th wave, you’ll have to start the whole stage again. This is where many players will be put off as absolute perfection is required to progress past the initial stages, even on the casual difficulty setting it’s tough. Usually, perfect scores are only required to unlock bonus content in a game. This knuckle-gnawingly difficult aspect of the game to merely move forward is a sadistic beast.

But you will keep trying despite knowing the slightest lapse in concentration or even bad luck will ruin everything. There are some genuinely heart-pumping moments when a monster emerges from a hail of tower attacks and limps towards your unprotected village, while you wait, powerlessly, for your weapons to reload.

It’s like that bit in the film of The Lord of the Rings: The Two Towers during the battle at Helm’s Deep when Aragorn’s franticly ordering the archers to take out the Uruk-hai with the torch rushing towards the wall-breaching bomb, as you sit there screaming “Bring him down!” at your PSP. Maybe avoid this one on the bus then.

The ‘Deluxe’ of the package is referring to an extra island, extra videos, more towers, new enemies, music and concept art now available. The basic but nicely drawn visuals look almost identical to the PS3 and the controls transfer over easily too. Co-op multiplayer is a great new inclusion and helps ease your war-torn mind from all the time coping on your own.

While the controls and gameplay aspects are easy to pick up, the challenge inside is severe. However, the game feels like a much better fit for the PSP than it does on the PS3 so if you fancy a challenge you should take a look.