21. Rat On A Skateboard - £0.59
The third outing for Donut Games mascot Ratty sees him ditching his uncool scooter and instead getting all 'gnarly' and 'rad' doing various skateboard tricks. Gameplay-wise, Rat On A Skateboard is ultimately another one-thumb survival game with a few twists, but its various modes and great character make it an essential purchase.
22. Pac-Man Championship Edition - £2.99
When Pac-Man creator Tōru Iwatani returned to his yellow hero in 2007, the result was the astonishing Pac-Man Championship Edition, which turned a tired (if still amusing) arcade game into a high-octane and brilliant Xbox Live Arcade title. The iPhone release retains the game's addictive qualities, but adds a ton of extra content. Here's hoping semi-sequel DX arrives on the iPhone, too.
23. Cut The Rope - £0.59
One of the few games to challenge the chart domination of Angry Birds, Cut the Rope proves to be prettier and better to play than Rovio's title. The aim is to get the candy into the maw of small green dude Om Nom. This is done by manipulating ropes, pulleys and other systems, combining action and puzzle-solving, but without the annoying randomness of Angry Birds.
24. Linkoidz - £0.59, universal
Linkoidz is reminiscent of cult classic Magical Drop, itself an 'evolution' of popular match game Puzzle Bobble. You destroy aliens by matching three of them, or their weight eventually crushes your guy's shield and he's devoured. The hook is that instead of switching aliens Bejeweled-style, you suck one into your gun and fire it back. Fast-paced and great-looking, this is a hugely enjoyable iOS action puzzler.
25. Super Mega Worm - £0.59, universal
Super Mega Worm brings to mind cult film Tremors and pixelated 1980s videogames as you 'become the worm', terrorising all on the surface, to rid the planet of polluting humans. The challenge is relatively slight, but the game's humour and Game Center support means you'll regularly come back to it - and it's a hell of a lot better than the similar but tedious Death Worm.
26. Castle Smasher - £0.59
Although it looks similar to a simplified and angular Angry Birds, Castle Smasher plays rather differently. The game's firing mechanism (for lobbing stones at castles) is more precise, and you also have to defend your catapult guys against attacking knights. Randomly generated levels provide limitless gameplay after you work through the well-judged challenge levels.
27. Osmos - £1.79
At once resembling intergalactic conflict and microscopic warfare, Osmos is one of the strangest and most beautiful iOS games. Your 'mote' is propelled by ejecting pieces of itself, and the aim is to absorb motes smaller than yours and avoid those that are larger. Varying level types and utterly gorgeous visuals and soundtracks make this one of the finest games on the platform.
28. Piyo Blocks 2 - £1.79
Bejeweled has spawned a number of clones, the best of which is Zoo Keeper on the Nintendo DS. Piyo Blocks 2 is very similar, offering a fast-paced match game with several modes, including time attack, target capture, and more. Essential if you're a fan of the genre.
29. Axe In Face - £0.59
If Plants vs Zombies and Flight Control were mashed into a sticky pulp and uploaded to the App Store, the result would be Axe In Face. This charming line-drawing/castle defence game has Red Beard desperately defending his daffodil field from other Vikings, mostly by chopping off their heads with his magical axe. Getting through the game won't take you terribly long, but you'll be hard pressed to get more fun from 59p.
30. Beyond Ynth - £1.79
Beyond Ynth is a puzzle-oriented platform game which tasks a bug with collecting gems to bring back light to his kingdom. Each level comprises a number of 'boxes' that must be entered and correctly rotated in order to proceed; grabbing gems requires some serious puzzle-solving abilities, and one wrong move often means death by lava, ice or fire.
Mercifully, the latest Beyond Ynth update does away with the 'start the level for the 50th time' mechanic, enabling you to rewind progress past errors. Even so, it'll take you many hours to grab those gems.
31. Galaxy on Fire 2 - £5.99, universal
Doffing its cap to BBC Micro classic Elite and online MMO EVE, Galaxy on Fire 2 catapults you into an epic galactic adventure. You get to chart the course of your life, balancing trading, combat and other tasks. One of the few iOS games that can truly be described as epic, Galaxy on Fire 2 is well worth the entry fee.
32. Trainyard - £0.59
Trainyard is an innovative puzzler which will soon have you gnashing your teeth in frustration. The theory is simple: get each train to its like-coloured station, by drawing tracks. There's no time limit or score, so you'd think Trainyard would be a simple, relaxing experience. Soon, though, you're immersed in dealing with multiple trains, split tracks and colour theory, perhaps gaining a newfound respect for the British rail network when it's having problems. (OK, perhaps not that last thing.)
33. Infinity Blade - £3.49, universal
In screen-grabs, Infinity Blade visually resembles a free-roaming RPG, but it's in fact a block-and-parry beat 'em up, akin to Karateka or Punch-Out!!, but with glorious modern-day graphics and huge swords. Basic RPG-style levelling up provides a little extra depth, enabling you to gradually tackle stronger foes during each 'bloodline', and the gestural sword-fighting controls are great.
34. Bubble Pets - £1.19, universal
With iOS devices having glass screens and no tactile buttons a whac-a-mole game might seem a curious recommendation, but Bubble Pets is great. You prod pets to make them fly off the screen in balloons, taking care to avoid each level's 'bad' pet. Now and again, bosses appear, and each of the environments is colourful and vibrant.
35. Need for Speed Hot Pursuit - £2.99
Technically superior and smoother racing games are available on the App Store, but Hot Pursuit gets our vote, for sheer thrills and excitement value. This one's arcade racing all the way, with you aiming to flee from the fuzz; alternatively, you can 'be the man' and smash racing syndicate members into submission (or race your corrupt buddies through deserts, forests and along beachside towns).
36. Strategery - £1.19, universal
Although a superior experience on the iPad's larger screen, Strategery is also an essential purchase for owners of smaller Apple devices. It plays out as a stripped-down Risk, but where 'countries' have a maximum number of armies. Despite its simplicity, the game offers plenty of tactical depth, and you must learn to think several moves ahead, especially when playing human opponents in turn-by-turn online games.
37. Pizza Boy - £1.19
Mario-style platform games rarely work well on iOS devices, but Pizza Boy is a good effort. Despite there being some cheap deaths in later levels, the game offers plenty of charm, good humour and decent level design. The controls rarely let you down, and the unlock mechanism for 'bonus' levels is interesting, forcing you to explore as you play the game.
38. Scrabble - £1.19
EA's take on the world's most famous word game is a good one, with a great-looking board, a decent solo mode, pass-and-play and local network play. Scrabble has some minor dictionary niggles, and EA needs a slap for not providing turn-by-turn online games, but otherwise this is a first-rate boardgame conversion.
39. Tilt to Live - £1.79
A great example of a simple, addictive mobile game, Tilt to Live has you fleeing from evil red dots of doom. You tilt your device to fly around the screen, colliding with bonuses to fire heat-seeking missiles and glacial ice bombs at your adversaries, for a few moments' respite. The game's slightly demented sense of humour adds to the fun.
40. Helsing's Fire - £0.59
An original puzzle game is a rare thing indeed, which makes Ratloop's effort - Helsing's Fire - all the more worthy of praise. The idea is to use the careful placement of torches and coloured tonics to banish demons.
Your main foes are objects that cast shadows, stopping your light reaching intended targets. It's an interesting dynamic, and the game's 120 levels take a while to beat, all the while charming you with great character design and beautiful graphics.
Sign up for TechRadar's free Weird Week in Tech newsletter
Get the oddest tech stories of the week, plus the most popular news and reviews delivered straight to your inbox. Sign up at http://www.techradar.com/register