The Zeta Project is a painfully mediocre show that doesn't live up to its DCAU contemporaries even remotely. The Zeta Project had any sort of intrigue dashed by executive meddling that the other shows could work around.
Both The Zeta Project and The Batman make Batman: The Brave and the Bold (even if the latter two were outside the DCAU, some episodes were created by DCAU staff - Zeta also had DCAU regulars) look like Batman: The Animated Series. Being kid-friendly and episodic isn't inherently bad, but both shows were definitely made for a singular target audience, with no real consistent bonuses for the older crowd unlike Bold which at least had mythology gags, varied voice acting, and creative scenarios going for it.
It's a shame when the best thing about The Batman and The Zeta Project are probably their themes for their respective opening credits / title sequences.