I just got out of a game. I made about 30 Sakata Spiders, 15 Mod. Sakatas, 15 Sakata MK-II, and about 15 Gladiators. My partner had about 30 Hover Tanks, Four Chronite Tanks, Four Black Queens, and 20 Meditecs.
When we clashed against our opponents, little trapezoids appeared that were coloured black, orange, red, and yellow.
I am pretty sure this is a raw explosion, that doesn't have the bubble effects it did in v5.3.