Collectable items in the form of blue crystals are found scattered throughout the game's levels. If the player collects 100 of them, they will earn an extra life along with a dragonfly icon, in which three icons are needed for the player to take part in a special bonus round involving a dragonfly ring chase.[8] In addition, the player can collect power ups which will enable them to defeat enemies instantly. These come in the form of "zap" and "spit" attacks; the former allows Bug to fire missiles made out of saliva, and the latter unleashes a bolt of electricity.[9][6] The levels featured in Bug! are linear – the player may only move in four directions despite the game appearing in full 3D.[1] In addition to walking on a grid axis, the player-character can also walk up walls and upside down.[6]