If your idea of a raft is something akin to that hunk of junk Tom Hanks escaped on in Castaway, you should see what the ninja of Ninja Raft have come up with.

It's nothing less than a hulking battleship, complete with a modular design for bolting on gun turrets and other defence mechanisms.

Makes you think that these ninja should drop the skulky, stabby-stabby malarkey and take up shipbuilding.

Prepare to be boarded

In actual fact, it's you that does much of the shipbuilding in Ninja Raft. Your crew of ninja start out on a small hub craft, and it's up to you to attach components to make it more formidable.

Not that you'll be attacking anything. Rather, you're preparing your undermanned craft for inevitable boarding and pilfering from waves of meddlesome pirates.

Once these swarthy scoundrels have alighted on your craft, you must touch and drag ninja towards them, at which point they'll automatically engage. The numerically superior force wins.

The combat section, then, plays out a bit like classic iOS strategy game Galcon.

Ship-rights and wrongs

The whole raft-building thing adds an extra strategic element. The idea is to bolt on sections of hull containing coins, which the pirates will target, and build in defences to protect them.

You might add spikes that slow the pirates down, or a whopping great direct-fire cannon (speed up reloading by throwing additional ninja onto it) onto the side.

In truth, the building phase feels too random, formless, and limited for its own good. You're only given a small range of pieces, and your raft invariably ends up frustratingly lop-sided, rather than the carefully constructed death trap you envisaged.

Raft of problems

This has a knock-on effect for the attacks themselves, which feel like frantic screen-scrub-a-thons rather than a measured defence of a (relatively) static position.

It's also a struggle to squeeze everything in on an iPhone (at least, anything pre-iPhone 6), requiring much pinching to zoom in and out.

This places additional strain on the swipe-to-direct controls, with your ninja never bright enough to realise the attacking threat in the adjacent square.

Getting overrun and losing a level, meanwhile, leads to an irritating mini-game, whereby you must uncover your lost raft pieces in a random game of battleship. You won't do it in one turn, which means you'll opt to watch a video to earn five more tries several times.

There's a good idea for a game here. Mixing Galcon-style simplified strategy with tower defence and dungeon building? I'd play that.

I just don't think Ninja Raft is quite the game that successfully realises those ideas.