Note the clever illustration design -- with its fisheye-lens perspective and careful bat placement, the grinning kid could have a crewcut or a ponytail, and the eyelashes are not quite feminine unless one chooses to see them that way. Even the tagline seems to indicate a certain wrestling with gender identity -- how else to explain this bizarre non sequitur?
It's Baseball Action So Authentic, The Only Replacement Player Is You!
Can you replace yourself, then?
At any rate, the enthusiastic... child... in the ad seems absolutely thrilled with the Batter Up, but the copy doesn't give us much information about exactly how this electronic bat is supposed to work. There was no pack-in game designed specifically for use with this after-market controller, so the device would ultimately have had to translate the player's swing into a simple button press for whatever baseball cartridge was in use. There are a bunch of buttons visible on the bat's midsection in the artwork, but none of them are clearly labeled.
According to Wikipedia, the product's manual claimed compatibility with a number of baseball cartridges, and this ad indicates that three 1995 baseball titles included coupons for a discount on the Batter Up controller, which would imply that those games were at least playable with it.
But it took Nintendo to get this concept right a few generations later, with the Wii Sports baseball game that wisely focused on batting only. I suspect most Batter Up owners found the thrill of swinging a 24" miniature bat paled next to the irritation of fielding with its tiny cluster of buttons and DIP switches.
Switch hitting, anyone?