COLLECT-A-KEY

Work your way up the screen collecting the keys as quickly as you can.
A monster, a hammer, an electrified wall and a moving wall have joined
forces in an attempt to hamper your progress, and they should be avoided.
 If you manage to collect all fifty keys, you must return to the flashing
wall at the bottom of the screen.

Collect-a-Key was written for the 16K Spectrum by Mark Freeman
of Colchester, Essex.