The feeling of the arcade game is perfectly reproduced. Congratulations! Just a few criticisms, I hope constructive:
1 - No bonus frog at 5000 points
2 - Difficulty level very high already at the third level
3 - As soon as the crocodile appears, you can still enter the den (while not here)
4 - Bug of the invisible fly absent (just kidding :-))
Again, congratulations, beautiful conversion!!