Bonus Stage (Sonic Spinball 8-bit)
From Sonic Retro
The Bonus Stages in Sonic Spinball are sidescrolling stages similar the those of the in the main game. The layout is less complicated and comprises of three interconected cages. The passage to the next cage is opened by collecting at least half of the available rings in that section. Each level has Rings, bumpers, treasure boxes, and mechanical birds (or fish). The treasure boxes can be opened by being jumped on three times and will award the player with 1000 points, 10 Rings, 1up, a continue, or extra time. If the bonus level is completed in time then you will keep all the bonuses acquired, but if not you will lose everything collected.
Bonus Stages are accessed the same way as in the Mega Drive version and are played in between levels automatically. Unlike the Mega Drive version, all the cameos from Adventures of Sonic the Hedgehog and SatAM characters have been dropped from these stages.
Instruction Manual Description