First of all, love fanfic. I think it's a great way to hone writing skills and have some fun.
Strong points:
Your overall concept is good. It seems like you have a vision of your setting and your characters.
Dialogue is very natural
What you mainly need to work on is showing vs. telling. For instance, you have your setting. Great start...for your notes. Your story should unfold gradually. Show the audience pieces of your setting.
For instance, when Buzzy was born, you can describe some of the setting then. You want to spoonfeed it. The backstory can come across more effectively if you reveal it slowly while keeping the action going. Same goes with your characters. Show the audience as you go along who these people are.
Second, you're getting a bit wordy in places. Basically, if you can what you intended in fewer words without giving up meaning, do it. For instance, instead of this...
Approximate 150 years ago, a research colony far out into the secluded countryside was experimenting with a shrink ray prototype. The colony was home to hundreds of people and families, in an attempt to create a scientific community. Their main focus was on technology and biology. Inevitably, something went wrong one day. During a test run, the shrink ray began to overload and exploded, causing a chain reaction. The whole colony, along with much of the surrounding wildlife was shrunken down to about a mile in size, the average adult becoming about an inch tall.
Cut it down so it's more like this...
Over one hundred years ago, scientists created a research colony, home to hundreds of people, far in the secluded countryside. Their focus was technology and biology and were experimenting with a shrink ray prototype when something went wrong. During a test run, the shrink ray exploded, causing a chain reaction, and the whole community and its surroundings were shrunk down. People were an inch tall, and the wildlife became like miniature toys.
See how it gets the same point across, but in fewer words? Your audience will pay much more attention if it's shorter.
Finally, pay attention to your grammar. For instance...
Maybe this wasn't so bad after all..?
Just put a period. It's just as effective.
I hope this was helpful. Happy writing!