The Circus Mystery by DTenso Games is a classic MSX platform game, available in English and Spanish.
In this game, you fight off aliens who took over the circus. Make the red key appear at each stage and finish the level by unlocking the gate for exit. Save the entire joint from the nasty space creepers, who invaded the land only to possess the circus animals. The food helps you gain score and unlock more stuff. Jump and climb the innards of the tent to complete each level.