Robo

You can have too much of a good thing apparently. Scientists have proved it experimentally by continually pleasuring lab rats until they drove them into deep depression. Imagine groups of cocoa-stuffed women actively ignoring big block Hershey bars; sticky adolescents starting to cry when asked to level-up their eleventh WoW avatar; even fast-talking politicians who choose to stop lying because the thrill has gone.

But a more interesting question is how much of an average thing can you endure? The average thing contains some pleasure so moderate over-exposure can be enjoyable, but the fall-off is often surprisingly quick. And that's the state of play in which we find ourselves in during the 76 – count 'em – levels of HeroCraft's maze puzzler Robo.

The first handful of levels are fun. Playing as Robo, you start each one in the middle of a confusing array of laser beams, mirrors, rocks, and bombs. These are your building blocks for reaching the seemingly unreachable exit, manipulating them to clear a path.

Rocks are blocking elements used to create gaps in laser beams. Mirrors, of which there are two orientations, are used to direct said lasers. You can, quite helpfully, redirect laser beams to destroy the generators themselves. Finally, if a laser hits a bomb, after a brief delay, it will explode Bomberman-style, destroying anything within its blast area.

Frankly it's surprising the amount of variation that these simple objects, combined with the topology of the level can generate. The trick is that you can only push objects around each level; as such, you have to be careful about how you move things around and tackle each stage. For example, if you end up pushing something against a wall, you'll then only be able to move it vertically or horizontally (depending on the wall's orientation).

During the earliest, simplest levels, this required attention to detail is welcome. When you start to deal with more complex manipulations however, you find yourself increasingly frustrated by simple mistakes that prevent you from finishing a level. There is a one-move undo option, but often you have to restart the entire level, potentially losing minutes of work. Of course, there are also immediate deaths when Robo gets caught in a laser beam or bomb blast and you can't undo those.

It's a situation not helped by the touchscreen controls. To move Robo one space, you tap above, below or right or left. Unlike the precision that would come with a keypad however, you find yourself making imprecise and hence erroneous moves. And when you start making these sort of mistakes because you're getting frustrated because you've just pushed a mirror against the wrong wall again, you find that you're over the limit of exposure to the average thing.

Yet let's not get too downcast. There is mental enjoyment when you crack a level. In the most satisfying example, all available objects will be required at least once, giving you a logical process to work on. In this way, you find yourself moving the various elements around, experimenting with different approaches, until you've either solved the puzzle or given up. The levels do get hard quickly (level 8 is a real bitch – see our PG Tips section for the solution), particularly as some contain red herrings to further confuse you. This seems a bit rotten.

With more care, the game would be more fun. Tighter control recognition would have been good, as would the option to skip over a level if you're stuck. It would also be great to have the option of one save per level. Additionally, a prompt informing you of when a level can't be completed and allows you to retry from the start wouldn't hurt. Not to be, at least in this version. Robo therefore remains that rare example: an iPhone game that because of control issues is perhaps better experienced on a smartphone.