These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Hoshi Saga
Guide Dang It: Stage 9982 in Dokuringo has a solution unrelated to the original puzzle, stage 77. It also has to be found in a field of 35 blocks with four positions each.
Tear Jerker: The solution of the final puzzle of Minna no Hoshi Saga, titled "Star Commando". It's implied that the girl succumbs to her illness and dies, and as the guy takes a photo of the night sky, he cries.
That One Boss: The Final Boss of Ringohime isn't so bad once you know how to avoid its moves. In fact, you have a regenerating shield and infinite lives for this. Then you face it in the final stage of Dokuringo... where you only have one hit point to beat it- get hit once, and you have to start all over. The game will give you an option for Mercy Mode shields if you fail to beat it, but this locks you out of the "good" ending.