Based on this youtube series https://www.youtube.com/playlist?list=PLB85864F4E46196A9
Differences being, it is made in JavaFX, using some design patterns, with more towers, enemies, levels and the addition of power-ups.
Intensity factor makes more and harder enemies spawn, it increases with time and when killing enemies.
Hold shift when clicking to place multiple towers if you have the gold.
Made in Netbeans, should work just fine if you import it into that IDE. Had issues with compiling it into a working .jar file.