If you make it to the boat at the end, you lose all of the crystals and experience you gained on that run. You should get both.. and maybe a bonus for catching and destroying the boat.
Couple of immediate typos pop out... you pull the "hammer" on a gun.. not a "hummer"... kinda funny though... and I would put "left" instead of "leaved" on exit.
Good game... if the high level guns had continuous fire, it would make it too easy. I started out upgrading the Money Skill to level 4 and was able to buy whatever weapons I needed pretty quickly. Finished with 3 multi-guns and the big vacuum.. it made the emperor simple.
To kill the monkey you need the golden cart, hangglider and bat... you have to either hit the bananas it throws ot the bombs on the clouds at the monkey. The good news its that you can kill it over more than one attempt.
A "back" have been added and "Esc" to go to menu ;)