"Using all the seeds (the colored words), try and make a garden of words and join the other gardens below!" ← So for the current garden (should change tomorrow) you need to use 音/おと and 飛び出す/とびだす in whatever you write. You basically just make up a sentence, short story, etc., that contains those words.
If you go to a different one, it would be whatever the coloured words are there. https://app.renshuu.org/games/... ← for this one it would be 青/あお, 赤/あか, and 黒/くろ.
Do we have to use every single word listed in the garden?
Yes, it says "Using all the seeds (the colored words)"
You *can* get away with only using some of them — I've been told to only report gardens that don't use any of the words — but the point is to use all of them.
Edit: Here's a quick example (for this month's garden): 夜になると、赤ちゃんは犬に乗って空を飛ぶ夢を見る。
Doesn't have to be perfect or anything
Tip: You can look up any of the words in the dictionary and check out the example sentences. Helps a lot with verbs.