Same here.
It throws an exception like this:
uncaught exception: abort(-1) at jsStackTrace (Grapple-Sim.wasm.framework.unityweb:8:15620)
I liked the game's concept!
It's easy to pickup, yet lefts a lot of room for replaying.
I can even imagine it as a more developed idea - think of roguelite exploration with some rpg elements/upgrades, plus some base-building and interactive enemies (mobile artillery, patrol planes etc).
p.s. would you like to add a download for an offline version as well, please?