see my post on a push/pull spinner here). If you don't have a push/pull spinner, you have to move with the js, aim with a spinner and use a thumb or something to shoot. If you don't have a spinner at all, it's not so bad, you have to use the MAME control setup to assign one button to rotate left and another to rotate right. If you setup the fire button to be between the two rotate buttons, it's still pretty intuitive. But, let's be clear, this game is at its AWESOME best when you can hold down the spinner to fire. Then, you just move around the screen with the JS and constantly move the spinner around to kill your attackers on every side.
The graphics are fun and a little cartoony. The most important graphic feature is that the boss at the end of level one looks just like my cats' butthole. I'd snap a pic, but it'll be better for you to discover it on your own.
The other great feature of Forgotten Worlds is the shop. I love games where you can periodically purchase your own power-ups from a wide array of choices. During the game, you get points for killing and also collect blue sparkly things that increase your "Zenny" - that's money to you and me. Don't know where they came up with the word "Zenny", apparently Capcom used it from time to time. Anyway, at periodic shops, you can purchase all kinds of crap - and of course, the stuff gets cooler and more expensive when you have more Zenny.
Of all the games I've discovered on MAME that I never played in the arcades, Forgotten Worlds is among my favs.