That was very fun, and I love how the baby gorillas stack up on your back. I really enjoyed the retro style gameplay, it reminded me of games like donkey kong and pac man. The graphics worked really well and even the text along the top gave it a nice arcade styling. Here are some ideas/thoughts...
- a banana powerup, when you get it it works like a power pellet in pac man, allowing you to go into ape mode and knock out the leopards.
- it is kind of weird that the lepords dont attack the babys but it makes sense for the gameplay, not sure how to message that better to the player.
- would be nice to see more stage variety as the game progresses. maybe mix it up with some different enemy types, or hazards to avoid.
- you can use the release build of littlejs for better performance and it will remove being able to press escape to bring up the debug mode.
- some animation on the main player would go a long way, even if it was just a 2 frame cycle like the lepords.
Great work on this game! You should consider putting it on newgrounds with some achievements for people.