A good story thus far, though a few things. Your characters are slightly unrealistic. I mean, if I fell through the ground into a group of strange freaks in lab coats, I'd be doing more than sharing a worried look with my Pokemon. I, personally, would be running for my life or battling like heck was on my heels.
It also seems a little odd that the scientists don't have a better security system than that... or at least some sort of support under the decaying floor. Not very smart for people labled "scientists". It's just a little unrealistic.
The only other thing is that Pokemon speaking like they do in the anime gets really annoying, fast. Every time the Sneasle is speaking, it doesn't need a speech. It could merely nod agreement or express worry.
But the frame of the story is good, if a little unoriginal. Keep it up, and I'm sure you'll improve!
Who's that returning from the depths of forum ghosts past? Oh! It's me!