From the web site of one of the authors, Steve Wallis (http://www.socialiststeve.me.uk/games.htm):
Push apples onto monsters, move under apples to let them drop onto the monsters or throw a ball at monsters, and eat other fruit on the screen to progress to the next level. For a big score at an early level, you need to fill in the hole so that five bonus monsters appear one at a time; if you get the final one with an apple rather than the ball, you get 800 points, or even more if the apple has hit another monster first on its way down the screen. At higher levels, you can sometimes get very big scores by pushing an apple onto a big stack of monsters. Beware of the vicious strawberry monster which appears if you take too long! Sean provided the graphics, but otherwise I wrote the game completely. It was based on (but better than in my opinion) an arcade game I saw called Dig Doug. Fruity Frank is extremely addictive, and I recently received a huge complement from someone on the internet who said that Fruity Frank is the best game ever. I disagree; in my opinion, Buster Block is better.