add stupid explosion effect

public/js/starbugs/render/particle.js

@@ -0,0 +1,39 @@
+class Particle {
+	constructor(effect, x, y, xvel, yvel, color, size, behaviour, lifetime) {
+		this.effect = effect;
+		this.x = x;
+		this.y = y;
+		this.xvel = xvel || 0;
+		this.yvel = yvel || 0;
+		this.color = color || '#f00';
+		this.size = size || 1;
+		this.behaviour = behaviour;
+		this.lifetime = lifetime * (1 + (Math.random() - 0.5) * 0.5) || 100;
+	}
+
+	tick() {
+		this.x += this.xvel;
+		this.y += this.yvel;
+
+		if (this.behaviour == 'sizzle') {
+			this.xvel *= 0.98;
+			this.yvel *= 0.98;
+			this.x += (Math.random() - 0.5) * 2;
+			this.y += (Math.random() - 0.5) * 2;
+		}
+
+		if (this.lifetime-- <= 0) {
+			this.destroy();
+		}
+	}
+
+	render() {
+		let x = this.x;
+		let y = this.y;
+		this.effect.pallet.square(this.color, x, y, this.size);
+	}
+
+	destroy() {
+		this.effect.particles.delete(this);
+	}
+}