I agree about noise, but you'd need to be careful. People would try to game it by giving themselves as many random chances as possible, by making many accounts or doing whatever was necessary.
It could undermine the legitimacy of the system, as well as put more load on the server.
As far as I'm aware, the rule is if the first syllable starts with a vowel, phonetically.
In your example "MVP", the first syllable starts with an "em", so a vowel. In "Minimal Viable Product" the first syllable starts with the consonant sound.
I had a major pain with this rule when dealing with auto-generation of some API documentation. It ended up just being an issue of detecting/guessing if the text was an abbreviation or some weird CamelCase thing.
I'm guessing from other comments that it checks logins on a wide variety of sites, some of which may be NSFW. Some employers might not like you accessing NSFW sites.
I haven't played it yet, but I've played several of Zachtronics games in the past.
They generally don't teach you technologies that exist in the real world. Real-world concepts are usually just used as a way to make the mechanics of the game more accessible (Spacechem and KOHCTPYKTOP are good examples of this)
However, their games are very programming-centric, having programming skills makes them much more accessible. Their game TIS-100 is literally just assembly programming on a made-up architecture. I wouldn't call them "educational games", but they're certainly very mentally involved.
I worked at a fast food place back in high school, I often used this approach to a pretty effective degree. The only issue that can arise is when your increasing friendliness causes the person you're dealing with to get irrationally angry and do something rash, such as throw a cup of coffee at you.
It was pretty painful, but the laughter the situation induced was a nice distraction.