Let's see... the notes that jump out at me are as follows:
The sound effects may be part of the game-and-watch idea, but they're really really loud and kind of ear-piercing when played in rapid succession.
I feel like more could be gleamed from the concept by actually animating the characters in a pose-to-pose method, like the game and watch itself. You've got a bit of that, but when characters animate fluidly, it feels wrong.
In writing terms, if you're going for a dramatic bent, it didn't quite land, and if you're going for comedy, then the best jokes may not lie in absurdism (don't make deals with green dinosaurs isnt quite as funny as it feels it should be.) but instead in jokes about the presentation, like if the stalactite had had a game-and-watch position shadow on top of where the kid was standing before it fell on him. I dunno.
Still, decent start!