I don't think get works for exported browser games, and the version I have on my computer is halfway through an update I never finished which still has some bugs. If you just want to play this offline though, you can download and play any itch.io browser game offline with the app, which can be found here.
And I also find that the demo level of this is way harder for me. Stele, a copy of this game with different graphics and without the editors, I can beat more quicker. It requires VERY PRECISE timing in order to get past the spikes, because 99% of the time, I miss those green balls that make you reach the green heart and finish the level. TIC-80 really needs savestate support!
I wonder why you never released this on the TIC-80 website before Stele was released.
I don't think I even knew the TIC-80 website existed when I made this. If I ever make any other TIC-80 games I'll be sure to put them on there. And yeah, all my games are way too hard (I can barely even beat the demo level now).