A tower defense where damage is a matter of pitch, your beams only bite when their tune matches an enemy's color, and some foes only fall to a blended note.
Defend the Core at the end of a winding lane. Place emitters beside the path and tune each one to the color of the enemies passing by, a matched frequency melts them, a mismatch does nothing. Overlap two emitters and their beams mix into a new color, the only way to crack enemies that resist any single pure tone. Survive ten waves to win.
The lane, the Core at the end of it and the emitters placed alongside are tower defence in its standard form.
The original mechanic is colour. An emitter only damages enemies of its own frequency, and overlapping two beams mixes them into a third — which is the only way to produce the colours you will eventually need.
That mixing is real optics, not invention: additive colour is how overlapping lights combine, and it is why red and green beams make yellow. It gives tower placement a second dimension, because two towers positioned to overlap can do something neither can do alone.
Resonance is an original free browser tower defense that turns armor into a frequency-matching puzzle of color and harmony. Beat the ten-wave campaign and an endless mode opens up. Built in-house, no download required.