Ring Run Circus starts off so well. It's a clever little action-puzzler that sees you taking control of a unicyclist. You ride around a series of interconnected rings, collecting stars and searching for the key that unlocks the next level.

It's almost effortless fun, and at first it looks it will be a neat little game that's not too taxing on the grey matter, with a decent level of challenge to boot.

But then things start to go wrong. It piles on new obstacles that weigh down the pure gameplay of the first 20 minutes, and soon the grin has been wiped off your face and you're gnashing your teeth in frustration instead.

Run out

You control your unicyclist with some simple screen-presses. Holding on the left of the screen makes you spin around the outside of the ring, and releasing your thumb lets you spin around the inside of the ring.

Tapping on the right-hand side of the screen performs your unicyclist's special move. This might be a graceless jump through the air, or a two-handed slap that knocks back enemies and stuns them for a moment.

If you're on the outside of a ring when you run past the place where it attaches to another one, you'll make the transition, nipping onto the next ring and, if you get the timing just right, getting a cheeky speed boost.

To begin with, weaving through the different rings is fun. You'll hop over obstacles, bounce around on springs, and dodge out of the way of lumbering elephants.

Circus act

But then the game starts to drop more and more challenges in your path. Moving rings are a horrible headache, and the speed boosts you get when transitioning become more of a help than a hindrance, spitting you onto rings you never wanted to end up on.

Then there's fire, other riders that steal the keys from under you, and bears that ride around pushing switches and shoving you over. The fun slowly drains away and you're left feeling a little hollow.

It's a shame, because the first chunk of Ring Run Circus feels like a breath of fresh air. Dig deeper, though, and you'll run into a blast of frustration that's difficult to get past.