It looks like the game is part of Chrome but not Chromium, so it would be under Google’s copyright. So if you mean a copy using the same assets then no. If you mean can you create an endless runner featuring a dinosaur, yes

This already exists

Probably legal unless you use their art.

Could they sue the hell out of you, block the game on app/play store and generally make your life miserable if they felt like it even if it would not hold up in a court: Yep.