Suggestion: Don't capitalize any words when picking the right words to form a sentence.
One of the games involves you reading a sentence in English and then choosing from a list of words to reconstruct the sentence in another language. I'm learning French, so if I'm asked to translate "He is rich" into French, and two of the words are "Il" and "est", then I know that "Il" is the right choice, as it is capitalized and "est" is not. It feels like cheating, when I rely on whether a word is capitalized or not to make my translation.
It would be kinda problematic with languages like german, because we write the nouns capitalized, and there are many words that are written exactly the same, just capitalized if it's a noun and not capitalised if it's something different. Additionally: "Sie" means "you" (polite) and "sie" means "she"... This list goes on and on, so I think it would cause more problems than it would benefit.