Some games just make us feel good – the music cheers us up, and the mere thought of having a spare moment to play again gets us excited.
We haven't had an app like that in a while, but Run Roo Run! is as near perfect as a pick-up-and-play title can be.
There's only the one control – tap to set Roo running, and tap any time you want her to jump.
And why does Roo run? She runs because someone's stolen her joey (that's a baby kangaroo) so she goes on a journey from Perth in Western Australia all the way to Sydney in the east in search of her lost pouch pal.
The game is beautifully illustrated in a clear, 2D cartoon style and the makers have nailed the music without making it too abstract, nor too annoying.
Each level is only one screen wide – there's no scrolling here – and Roo comes across a wide variety of obstacles along the way. These range from simple cacti and bushes to the trickier retractable spikes which can prove an excruciating test of timing. Other items include springs to bounce off, barrels to roll inside and floating icons that upend gravity.
Run Roo Run! is easy enough that you feel like a Jedi master at times, but hard enough that it's a challenge. Each chapter consists of 15 "regular" (read: slightly too easy) levels which must be completed to get to the next set, but also an six "extreme" bonus levels which require incredibly precise timing and ensure you don't finish the game too easily.
Extra "bus tickets" and "slow motion help" can be purchased to get through particularly tricky levels, though we prefer to get there under our own steam.
There's a timer on each level, and depending how long it takes you to complete it you're awarded a gold, silver, bronze or wooden star. However, this can be cheated by simply resetting the level before each new attempt.
Run Roo Run! has over 420 levels and with 10 new ones being added each week, this is one of the finest and best value games we've played in a long time.