I found this curio in a Singaporean mall, having jumped off the metro to avoid the seemingly endless rush-hour for ten minutes or so. Sadly, we were kicked out, as the place was shutting, and didn't get to give it a whirl. My other-half, unsurprisingly, considered this fortunate.
All pertinent information found here. Essentially, it's a Sonic kiddy-ride/shmup. The only way to play is arcade/over air-conditioned mall, the ROM has never surfaced and is still much-hunted among collectors.
During the rush, it didn't occur to me to video the gameplay, auld CRT-flicky style, but this is how it plays apparently. Courtesy of Alpha3TheGull: