Overlander is based on the classic coin-op, Moon Buggy or something like that. This version is closest to a Dragon 32 game entitled 'Lunar Rover Patrol'. There is not another game like it on the Amiga.
To shoot small obstacles your shot must be moving fairly slowly, so fire early. The front of your buggy is more sensitive than the rear, so jump craters early too. All of the obstacles are possible, although some on the expert course are very difficult.