I think it's a great concept but some of the words that are a "valid word" doesn't make sense and a lot more polishing is needed. First the premise of the gameplay is neat and I think there's a lot of potential! But this definitely falls short from what I think could an amazing game. The hints / tips costing you time is also a nice gimmick!
But of course it has it's own problems. One is the valid word pool. I'll walk you through what I did: One round I got "a" and "bee" as the starting words. Ok then I start guessing stuff like "honey" / "sweet" / "nest" / "hexagon" ... Then I decided to hit the hint for the letter count. Oh it's a one letter word? Then I just started mashing all of the alphabet until for whatever reason "i" was the valid "word" to be guessed. Some other similar "valid words" fall into similar issues. I got <brother> and <?> sauce for my hints. <brother> is connected to the word I want while <?> sauce is a derived word to the word I want. The word was "Daughter" by the way, strange isn't it?
That is probably the biggest gripe I have with the game. I'm sure the word system their relation graph is extremely complicated to make! But I can't say I had the amount of fun I expected to have jumping into this game unfortunately.
Still the concept and gameplay gimmick is really good and you should definitely keep pursuing it! The issue I talked about isn't a problem with your creative concept, it's more on the execution that needs a lot more testing before I think the concept can really shine. For a 4-day game jam I'm sure it was extremely difficult to make all of these systems and I'm not discrediting your effort that you put in!