itch.io

Oh, I think you took my comment a bit too directly.  When I say use the arrow keys to move up to the box... I also mean using them to collect what's inside too. Use the Enter button to just open the chest. 

Sorry, like I said, click controls can be a bit spotty at times due to the nature of the engine. You're just going to have to use the keyboard input here, walk up to it with arrows and press enter.