Here's something that just came to me.
With so many similar-sounding words that are easy to confuse, yet mean completely different things, one of the most important aspects of learning Japanese is to avoid as many embarassing misunderstandings as possible, such as シャツをきった and シャツをきた.
Now, one funny thing about the brain is that it tends to remember funny or embarassing mistakes a lot easier than "normal" mistakes. That's because both fun and embarassement have evolved as principal mechanisms to make sure we enjoy learning, or don't repeat a particular mistake.
Which is why I'd believe it would be a great thing to add a line to the "You got it wrong"-screen that translates what you accidentally said during your last drill. Since not all answers are valid Japanese words, the option "complete gibberish" would also need to be included, but for the most part, I believe it would be a highly educative experience to see the meanings of what you just said, and imagine the implications if that mistake had occured in a social context.