Congrats Candice -
That is great achievement.
A 3 min presentation without slides & props is actually one of the best as you can really get the audience on your side by making your product story personalised to their context and showing it can solve a problem they face daily.
Asking a question to the audience and getting a show of hands to how many face the same the problem your product is trying to address - gets them warming up to you fairly quickly.
( you can see me trying this here
as an intro ice-breaker)
Also in terms of overall structure - if you follow Chip & Dan Heath's structure in story telling ( Made to Stick
is a great book, do get it if you haven't - unpacks this very well)
They advocate a structure called SUCCESS
S - Simple
U - Unexpected
C - Concrete
C - Credible
E - Emotional
S - Stories
I understand your company does games for teens with ADHD. You have a fantastic rich story right there.
For example following above - I would apply it below
Ask members in the audience for a show of hands -
How many are parents or know parents who have been faced with a situation where teens have been exhibiting XYZ behaviours? Did they wish they could seek clinical/medical attention without incurring huge fees etc?
How many parents would like teens to play more games to conquer ADHD? (unexpected angle)
I think by shaping your talk around the issue you are solving and having the medical data to back it up and make it credible would be very strong.
Here's a handy link for further reading:
All the best and let us know how it went -