Qwak for iOS full review
On Superior Software's Play It Again Sam 10 collection for the BBC Micro and Acorn Electron, Qwak was a quirky puzzler that added to the other four games within the collection. Later on, via Team 17, Qwak was released for the Amiga and CD-32; then even further on the author - Jamie Woodhouse - decided to go into self publishing and release a version for the Game Boy Advance (no longer available), PC and Mac.
More recently, Jamie has released a version for the iPhone and, just as with the Mac and BBC versions before it, it's extremely addictive.
The object of the game is to guide a green duck through seventy levels. Fruit and gems can be collected for points, various power ups are available as you progress through the game (giving enhanced armour, weapons and so on) and enemies are destroyed by throwing eggs at them.
The audio suits the mood of the game: when you need to move quickly because death is about to approach, the music changes mood to reflect the urgency and direct you towards the door.