Clash of Stone is tower defence played from the trebuchet. Waves of skeletons march toward your position and you launch stones at them, adjusting angle and power for each shot while the wave closes in.
The artillery element makes it more active than most tower defence — you aren't placing towers and watching, you're aiming every shot, and a wave that reaches you is a wave you missed.
Drag to set angle and power, then release. Stones arc, so distant targets need more power and a higher angle — and landing among a cluster is worth far more than a single hit.
In structure yes — waves advance toward you and you upgrade between them — but you aim every shot yourself rather than placing automatic towers.
Yes — a light browser game with nothing to install.