4 Extending The Game
Throughout the tutorial, it has been made clear that you only have the basic outline of the game here. Even if the game play doesn't change, some work needs to be done to make the game worth playing. The first thing to consider would be to make the Start and End screens that you expect to find in a game like this.
As discussed in the Design Document, there hasn't been much thought given to the flow of this game. Currently, it goes on forever with no real change in the game play. The game doesn't go anywhere.
One thing you could do to sort this out straight away is to introduce a time limit to the game. The player could whack moles for a minute and then you could see what their score is then. You could also set them a number of whacks to get within that time limit, increasing the number of whacks required to complete the level or stage.
A high score table might make sense with this type of game and easy to find out how to do in Game Maker.
You could also adjust the speed at which the moles move, the length of time they remain in the whacking position and how often they pop up their heads.
If you want to make the game progress even more, you could add other things that pop up occasionally. These could be things you shouldn't whack because you lose a life or health or lose some score.
The barrels and moles were designed just to make the game work. Some new sprites would really improve this game. You could do a web search for the Pie Bill Gates game for some ideas or come up with your own designs. Moles should probably pop out of mole holes rather than barrels.
When you successfully whack a mole, you currently get no feedback. Playing a sound is the least that you could sort out. A nice thwacking sound would be good, or an ouch. You could also have the word whack appear, rather like in a cartoon fight, over the top of the mole that you have just hit. You could then make this disappear a split second later. Alternatively, change a whacked mole sprite into a sprite of a mole which looks like it has been whacked. Don't forget to change it back when the mole is back in its hole so that a new mole will come out later.