The first project can be started by running Simulacija.java.
Left click can spawn circles which will be picked up by the red triangle. Red triangle can be paused using spacebar.
The second project can be started by running Aplikacija.java.
Selecting the pipe orientation in the right menu and pressing Dodaj will insert the pipe into the grid.
The third project can be started by running Igra.java.
Left click will spawn balls that will destroy the upper blocks. The bottom figure can be moved left and right using A and D respectively.