Yes, it's intentional to allow words that don't use all the letters. It can be very tricky to think of a panagram every time (word that has all 7 letters used at least once). Hence, we don't require every submission to be a panagram. I'll work on making the instructions clearer!

There is a bit of an interesting related sharp edge here. Sometimes the longest word for a given set of letters actually does NOT use all the letters! I've thought of a number of approaches to address this tension, but, opted to keep scoring dead simple in the end. I may experiment in the future on this topic though.

I'd also like to expand it to work with other alphabetic languages too.