Suggestions...
I'll just make a list.
* Don't show the entire "walking" animation every time the menu loads, just the first time. It gets VERY old if you're searching through the menu options.
* Don't allow the ability to click menu options until the whole menu has loaded up.
* It's easy to get stuck on the left side of objects. The player can be freed, but it takes a jump, attack, and directional button to do it. This was extremely annoying in normal situations, but downright stupid in the sniper level, as the player could not see where he was going.
* Falling does not kill the player, but requires 2 attacks in a row in order to get killed.
* Maybe it's just me, but having a mochiads ad at the beginning, followed by 2 more ads kinda pissed me off. Use the brainflay and newgrounds ads while you're loading.
* The moaning or mumbling or whatever in the background got super annoying.
* Two words... SPELL CHECK. You had TONS of spelling errors in the library books; seriously, just ask me, I will gladly proofread for you. I freely offer this service to anyone seeking to make any movie or game.
* Add the ability to scroll the map. It's kind of annoying to have to piggy-back stages just so you can get the map to scroll.