Thanks for playing it!
I'm going to make the pause indefinite & at-will, since it's buggy & annoying everyone (including me, lol). I mentioned this in my reply to Gatherdev in the general, but I'm going to make the progress bar much more obvious when it's filled - a jingle & much more prominent animation.
The issue with a "forced" Survivors style pause in this game, is that it's a bit more shmuppy than most of those, so getting paused, then kicked off once you pick an upgrade is a recipe for taking unfair damage.
Chests will also get a proper animation & probably a manual click-to-open thing in that box on the right. I was thinking about "key" items you can get which will improve your loot tier out of chests, so you could want to save them sometimes.