Not sure if you've already figured it out or if you're even still interested, but I'd guess this is using some form of WebGL to run the browser version of this game, which doesn't always work on phones.
SirMorp
Recent community posts
Looking at their patreon, they've got fairly consistent progress logs (most aren't public) going up and are currently working on 0.7.3, so I assume it's just down to slow update times since they can only work on this in their spare time. They've got dev-cycle posts open to the public though, so you can check those if want to see what/when stuff is coming.
I'm pretty sure the 'not getting future updates' thing comes from buying it on sale; if I understand correctly, you'llbe able to get it again a little later once they put it on sale again. I bought version .38 on sale for $5.00, and can download the newest 0.46 version without having to pay another $5.
If you pay $10 for the + version, will you then be able to buy the ++ version by paying another $15, or would you have pay the full $25 to get it even though you've already paid $10?
I ask because I'm interested in the ++ version but I'd rather start with the + version to make sure I actually like the game before going for the more expensive option.