Imogen

Imogen is a computer game released in 1986, originally only for the BBC Micro. It was written by Michael St Aubyn and published by Micro Power. It was reissued as the lead game of Superior Software / Acornsoft's Play It Again Sam 5 compilation in 1988 when it was also converted for the Acorn Electron. It is a platform game featuring puzzles.

The game features sixteen levels which are played in a random order. To complete a level, Imogen needs to obtain a spell fragment which will warp him to the next level or, after all sixteen have been collected and the spell completed, to the outside world, thus completing the game. The spell fragments are always placed somewhere inaccessible at the outset of the level, and obtaining the spell fragments requires some lateral thinking on behalf of the player.

Imogen himself is able to transform into three different forms, each with an ability unavailable to the other two.

Each level (consisting of a sealed cavern 4 screens in size) requires transforming back and forth between the forms to complete it. While it is impossible for the player to actually die during the game, the number of transformations is limited to 150, and using them all before the game is complete renders it unwinnable.