Genius idea for the theme, very cool idea for a game!
I loved this entry. I'm definitely average at estimating, lol. I really don't have a lot of suggestions or feedback to give you, I think that if you wanted to continue working on this it'd just be an issue of having more content or having dynamic content, like maybe instead of a t-rex some other, similarly big (but different) thing pops up, and then the game keeps going like that.
Honestly, amazing entry. Keep up the great work!