I got all four life hearts in a single playthrough before killing the end boss but never got this achievement?

Plated through the game, loved a lot of it! I'd like to report a bug with pausing. Sometimes when you pause quickly and unpause, the pause menu dissapears but the overlay still covers the game. I can hear the player jumping around and sometimes I can enter doors or die to reset it. Otherwise my only option is to quit. It happens a lot when I've just entered a room but I do not know if this is the cause. https://i.imgur.com/cjenPKe.png (image of the menu when glitch occurs) ...

I don't mind if it is short. Just curious. How would you describe the difficulty?

how many times do i have to shoot it? i need tips to complete this room please. too hard.

The game saved when you use a statue or exit the options menu. Game save files are located in following path: %USERPROFILE%/AppData/Roaming/Stencyl\ and as far as I know, game has trouble saving progress if your computer user profile uses certain letters in it, such as Czech signs like á and š. Running the game as admin seems to avoid this issue. Unfortunately, I cannot change the location where the game puts save files at the moment. Sorry about the inconvenience....