I love this game! The graphics may not hold up, and the solidity (bug-freeness) may be rusty, but the gameplay holds true. It honestly reminds me of Heavy Iron Studios' SpongeBob games, even if it's like a "diet" version of them, it's still good. The only problems I have with it are the lack of other characters besides Pinky, the Brain, and the Warners making actual appearances beyond cameos, and the difficulty being pretty inconsistent. The Pinky & the Brain minigames are much harder than the main game is, especially the digging one.
The graphics are meant to look cartoony, which they do pull off somewhat well, but I'd think it'd look even better if it more resembled that one Spongebob game on Wii (I don't know if it was made by Heavy Iron or not, but it closely resembled theirs) that was cel-shaded and the characters had cartoon-style outlines, and all of the textures had a comic-book-style dithering effect. That would've looked really good, but it would've looked even better if it copied the shading style of the show. The voice acting is done by the show's original VAs, so it holds up very well.
I can't say this is the best game ever, because it sure as heck isn't, but it's a lot better than the critics think it is, at least when it comes to the fun factor, and if games are meant to be fun, then isn't gameplay all that TRULY matters unless you're trying to reproduce another game in a different one, like making a Minecraft map of Pokemon with actual textures and an intro from the actual Pokemon game, like I'm doing right now on CurseForge and YouTube?
If a game is its own thing, then EVERYTHING ELSE should be second to gameplay since playing games and having fun with them is their entire point. for tech demos, graphics will probably trump everything else, but commercial games aren't tech demos and this CERTAINLY isn't. People care too much about graphics when graphics don't affect how fun a game is. Sure, graphics may help immersion, but that's really the only impact they have on the fun factor, if it even COUNTS.
The sound effects would fit right at home in the show too. I can only DREAD what the reboot is going to do to screw the show up in season 2... My friends know how I work, and they told me season 2's trailer would break me. My advice? Always stick with the original property. 99.999% of reboots are cheap cash grab garbage, and them making a joke about this in the Animaniacs reboot is just a "what we're doing is wrong, we know it's wrong, but we're gonna do it anyway" situation. I do wonder what the next Animaniacs video game is going to be like, and I can only HOPE it'll be more like this, in line with the ORIGINAL.