Looks like you were inspired by Resident Evil 4's inventory system. 

Take your time. Take as long as you need to make something great even greater. I hope your game gets as much attention as it deserves.

Your game is just amazingly fun.  I haven't really played many games that made me want to come back playing more. But your game is just so enjoyable. 

Is there a way to remap the controls? Because the controls for arcade pads feels a bit odd for me.  I kinda prefer street fighter arcade controls.

I've noticed some errors in your examples. Page 17 in the coding and text where it says "bat_x=bat_x+3" in the function move_bat(). In page 40 under the same function move_bat() it changed to "bat_x=bat_x+bat_speed" without any explanation.  Also on page 36 it says at the top "detect_collision" even though in previous examples say "check_collision".