WH20 is an awesome game. It's got fantastic rules that are easy to understand, yet provide alot of different scenarios and strategy.
The main goal is to advance to Wet Willy's. You do this by completing the lite shots and advance through the river. I like how the lite shots force you to play the entire playfield at some point.
While advancing up the river is the main goal, there are other scoring opportunities and diversions along the way. You can hit the targets to eventually lite Big Foot Hot Foot. There are whirl pool awards: whirlpool challenge, man overboard, lite extra ball, advance raft, mystery canyon, and 5x playfield. Since you can see the whirl pool award being earning it, you can select when to "use" a given award and this adds a great deal of strategy to the game. For example, you might time 5x playfield after locking 2 balls and having it lite for a third.
Multiball is also a blast, the jackbot increases if you hit the side ramp as the ball is served for MB. If you get one ball up the ramp 1x jackpot, 2 up the ramp 2x jackpot, 3 up the ramp 3x jackpot....AND if you have started 5x playfield....WOW! That's quite a rush and not an easy accomplishment. I don't think I have managed all that.
It's a really good game. Plus, you can practically rebuild it if you want an awesome example of the game. Pretty much all the parts are available: ramps, playfields, plastics, boulders, etc. It is a very, very expensive game to restore, but worth it.
Cheers,
Duane