Yeah, that sounds right to me. I'd have probably spotted it myself if their rendition suck Yong Yong's broken synthesiser. Obviously, music wasn't really NC's strong point. (well actually, I don't think they have a strong point but whatever)
Also worth pointing out that the gameplay music in Toy Bricks is a broken version of the tune from Magic Bubble/Octopus/Twin Fish/etc.
Edit: Just noticed that the transition effect in Dringle is taken from Battle City.
Also, call me crazy but I think the engine used in Vigilant bears a surpringly close resemblance to the flying stage from Super Contra X.