Boom! is a slot machine produced by WMS Gaming, (the gambling branch of Williams the arcade game manufacturer). This is an electronic slot machine, with a monitor instead of actual reels. The theme of this particluar machine is that of a 4th of July picnic. This is a five line machine with a total of 5 reels, and different versions will accept anywhere from 1 to 90 coins. This machine is usually takes 5 cent tokens, but some casinos have 25 cent and 1 dollar versions of this machine.
The symbols in this game are all related to food and fireworks, (rockets actually). Boom! has 2 different bonus payouts. The first is a small counter at the top of the screen that counts up every time the Boom! symbol appears. The player will receive 50 credits when this counter reaches 50, (a few things will trigger this payout earlier at a reduced rate). The counter will then rest itself. The second bonus is triggered by getting 3 identical symbols of barbeque food on adjacent reels, (they do not need to be on the same payline). This is the bigger of the two bonus games. The reels then vanish, and you are presented with 5 different rockets to choose from. Pick one, (using the touch screen), and it will launch off and explode. The bigger the explosion, the bigger the payout, (this can be small like 15 credits, or it can go into the thousands).
This game, (like most electronic slot machines), gives the majority of it's payout through the bonus round. You will find that your money quickly goes down the drain if you do not manage to hit the bonus round from time to time. These particular machines are very popular among senior citizens. You will rarely see one unattended in a crowded casino.
From the WMS Gaming website
Experience a business boom when you take off with the latest explosion in bonus screen games. BOOM!, like its popular predecessors Reel'em In and Filthy Rich, blows players away with exciting fireworks and 3-D graphics on the popular bonus screen.