Challenger is a Scramble-Defender game that should give most BBC owners a good run for their money.
Flying your ship across the screen you have a reverse option (as in Defender) and must avoid rockets as they launch skywards (as in Scramble).
You have three lives, a laser cannon, shields, and an unlimited supply of bombs. Bombing fuel dumps tops up your tanks; if you run out of fuel you lose a life.
The game has many levels, distinguished mainly by the speed and ferocity of the opposition. The first level poses no threats apart from fuel starvation and easily-avoided rockets.
At the higher levels, nasty little creatures rise from the landscape below and take pot-shots at you. They move fast, and at this stage of the game I was acutely aware of the absence of a long-range radar scanner.
Even ignoring the pause and volume controls, no less than seven keys are needed to play the game. Under normal circumstances, with no joystick option, this would present severe difficulties. However, not only do Joe the Lion offer you the opportunity to re-define your
own keys, but you can also allocate more than one function to a key. Assigning the shield, bomb, and fire controls to the same key makes the game a positive joy to play.
There are some tricky caverns to be negotiated at the higher levels. The graphics aren't bad, though there is a tendency to flicker. Challenger is definitely one of the better games available on the Beeb.