From Wikipedia
Superfrog is a 2D Platform game developed for the Amiga and then converted for the PC, developed by Team17 Software in 1993. (...)
The story (mostly conveyed through the introductory animation by Eric W. Schwartz) is about a prince (inspired from the Frog Prince fairy tale) who is turned into a frog by a witch. His girlfriend is then abducted by the same witch. He was subsequently sulking by the "River O' Despair" when he found a floating bottle of Lucozade, which made him Superfrog. The objective of the game is to find and defeat the witch, then rescue the princess. (...)
The game features an overt commercial tie-in with the energy drink Lucozade as a health-boosting powerup, similar to the Chupa Chups sponsorship of Zool, 7-Up's sponsorship of Cool Spot and Quavers sponsorship of Pushover.
There are 24 regular levels divided in six differently themed worlds. The goal of each level is to collect a number of coins and then reach the exit (the levels are also on time). Depending on the number of coins and fruit collected and on how fast the player finished the level a number of up to 15 credits are awarded at the end of each level. The player can then choose to either collect the credits for a score or gamble them in a slot machine-style minigame for more bonuses. The most important function of the slot machine minigame is the chance to win a level code enabling the player to restart the game from the beginning of the next level at a later time.
An extra level between world 5 and 6 took the form of a side-scrolling shoot 'em up called Project-F in homage to Team 17's own Project-X (even going as far as using a remixed version of the original game's theme tune). There were no coins to collect in this level, the only goal was to reach the end.
The game ends with a small boss fight against the witch.