Not until completion, and even after completion, it will not get an APK build cause Google is disabling APK installation, very, very, sadly, cause it was completely planned to be an APK.
Not at all, it's designed for mobile, but will be only playable from browser.
Indeed, the game is very bare bones, it's only available for playing so people following the project can always check it's current progress.
Thanks for reporting that bug, I'll post an update this week, fixing that, and adding new stuff.
Not a bug, here's the list of things that add +1 mistake.
1. Hunger ≥ 1
2. Health ≤ 25%
3. Sleepiness ≥ 3
4. Happiness ≤ -1
5. Discipline ≤ -1
6. Bond ≤ 0
7. Poops in Device ≥ 1
8. Weight ≥ 200%
The starting Zurumon that comes with the game starts with Bond=0, so that's why you'll see that Mistake=1 until the Bonding Mechanics are implemented.