My favorite three aren't in there. All Dexter's Lab themed, now that I think about it.
One was puzzle game where you had to bounce a laser off of mirrors to pop balloons. The second was kind of a Chip's Challenge kind of deal I think, where you as Dexter were running away from an out of control robot, and had to collect some computer chips or something.
And in the third game, Dexter was running, inexplicably, a record store? Dunno if it was a tie in for a specific episode I don't remember now, but it's quite a funny premise, and a fun game too.
If you worked on any of these games, thank you! I spent so many hours back then on those, and many others.
I still had dial up back then, and I couldn't stay online for long. Eventually I figured out that if I kept the website open, then disconnected (rather than closing then disconnecting, which was what my parents taught me), the games would still work. Which is obvious to me now, of course, but as a 6~7 year old, who had no idea of how any of this worked, I felt like an actual, proper hacker. I literally just had the thought, "wait, what if..." and was promptly rewarded. I've been chasing that high ever since :)
From then on, my evening routine after school was connecting, picking the 3~4 games I wanted to play for that night, letting them load, disconnecting, and playing to my heart's content. If I hacked anything that fateful night, it was my parent's main excuse to get me off the computer!
The mirrors one was part of the PC game[1], I remember it vividly.
[1] https://www.pcgamingwiki.com/wiki/Dexter%27s_Laboratory:_Sci...
The games you mention are Dexter's Laser Lab, Dexter's Labyrinth and Dexter MixMaster, by developers NetBabyWorld. Those games were originally their own game without the Cartoon Network branding. Labyrinth was based on Ninja Girl 1 and 2 and Dexter MixMaster was originally Tune Inn (that's why this one felt a bit off).
Since they were Shockwave based games they're not playable on modern browsers but they're playable with the Flashpoint Archive project. Huge timewaster, be careful. Better look for the games on YouTube :)