Graphical effects are used within Transformice to indicate certain events happening in game. The main effects seen by players are clouds, hearts, sparks and bubbles. Effects are visible even during nightmode, which can be helpful for locating things like the cheese or the hole
While mice cannot see past a small radius around themselves in nightmode, effects are still visible anywhere on the screen. This allows mice to pinpoint the location of cheese, gaps, the shaman, and the mousehole.