Thanks for playing! And yeah I hate that too, it was my first time exporting in html5 with gamemaker, if I knew it would be so small on the browser I would have done something about it. The download version allows for window resizing and is pixel perfect with out any artifacting or anti-aliasing shenanigans.
EDIT - I fixed it kind of , I used views in game maker and set them to 1280x720 however it came at the cost of making the hud smaller than indented and while it is a simple fix to scale up the hud I am afraid I am out of time and it also isn't very necessary to the gameplay.