I'm assuming the reason the same information about the doors is presented over and over in various maps is because you aren't sure what map they might choose as their first, although there are ways around this such as forcing a player to play a map with the tutorial/putting a global switch check. I don't think reading the tip about the green door is that useful after the 4th time.
There's a graphical glitch where if the character is falling really fast, they can end up below the position of the floor for a few frames (1?) before their ._y position is reset to the "minimum" for the top quadrant (yes, I coded for AS 2). Putting the check in the movement script would fix this (ex. if((character._y-speed_character_is_moving)<(minimum_variable)){character._y=minimum_variable}else{normal movement function})
Disclaimer: I only did basic coding in high school and my solution to this caused two "linked" (via actionscript, similar to the top/bottom thing) symbols to go out of sync, but I think it's possible to go around the problem.
Art direction needs some work, the moving platform is incredibly hard to see. Never sacrifice playability for artistic choice, unless necessary. Also, faster movement would be nice.
For a four man team I expected better results based on the tutorials available on the net, although this is your first game, so it's understandable (especially due to the low bugs)
I 1 stared since trying to move the cursor with a laptop's trackpad is (&^% impossible, fix the aiming code please so it doesn't mess up when firing/update once every 30 frames when firing or something.
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