Tumblepop (タンブル・ポップ?) is an arcade game by Data East released in 1991. It is considered a cult classic, and was later ported to the Nintendo Game Boy.
The game involves one or two ghost-busters who can suck monsters, ghosts, aliens and various other oddball characters into vacuum-cleaner-like devices and spit them back as bouncing/rolling balls. Expelled enemies function as projectiles that can damage and kill other opponents on the screen when colliding with them. The game's looks are reminiscent of Pang. Throughout the game, the player/s can collect letters of the alphabet found in randomly appearing bubbles in order to gradually spell the word "TUMBLEPOP", the progress of which is permanently displayed at the bottom of the screen. When completed, players are transported to a bonus level which gives them the opportunity to obtain higher scores and an extra live, although this level is strictly timed. The word goes back to default after completion.
Source: Wikipedia, "Tumblepop", available under the CC-BY-SA License.