Orborun is a brilliantly twitchy arcade game that sees you controlling a podgy robot who can turn into a ball. It's your job to lead the 'bot to a glowing portal at the end of each level.

What starts off as a pretty simple exercise in tilt or touch gameplay soon becomes a tough-as-robot-boots dodgefest that sees you weaving at breakneck speed through a series of obstacles and speed boosts trying to amass as many points as possible.

It makes for an entertaining experience with a good chunk of levels and plenty of replay value on top of that.

Abs-orb-ing

Each level starts with a choice. Do you want to use touch or tilt controls? Choosing touch makes for an easier game, as you can deal in finer movements, but there's something a little more honest and engrossing about playing Orborun with your iOS device's gyroscope.

You're rolling down a strip of track surrounded on all sides by a gaping techno-abyss. Stray too far off the track or miss a jump and you'll plummet to your doom. As well as staying on the glass track, you need to negotiate a variety of obstacles.

There are huge gaps to propel yourself across, portals to jump through, walls to nip past, and various point-scoring tokens to try and pick up without careening off into the bottomless void that surrounds you.

Finishing some levels is pretty easy, but trying to grab a high score on them is a nightmare. You'll need to loop through various portals, picking different exits each time, and risk everything to pocket score-boosts on the very edge of the track.

Roll for it

Orborun might not be the most distinctive game, but it's incredibly polished and well designed.

The 'retry' button is always close at hand, and the level design walks the line between fiendish and enjoyable almost flawlessly.

It's not without its problems, and some will find the later levels more daunting than enjoyable, but Orborun is a fresh and fast solo racer with enough interesting ideas and entertaining levels to keep you playing for a decent length of time.