More of an 'unintended consequence', but:

If you have a faerie in a bottle, and pick up another one, and choose 'store it', you get an error that you don;t have empty bottles, but the faerie isn't released. It's just wasted. You may want to fix that for future releases, especially if a player isn't closely monitoring his bottles. All you need do, is change it so that if it can't put it in the bottle, it re-spawns it close to the player.

That, or run a check to see if there are any full bottles, before offering the choice.

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In the L1 block puzzle, it's possible to misalign the block in the small room with the crystal switch. Again, I'm not sure if that's intentional, but it took me half-an-hour to realise that I botched it, with a misalign. Once I realised that, I reset the room and solved it quickly. The puzzle itself isn;t hard, just tedious; but that misalign potential has no recovery possible.

[Christopho]

Actually the fairy is not wasted, it restores some life if there is no empty bottle.
Ok for the blocks puzzle. You will realize that Zelda Mystery of Solarus DX is very puzzle-oriented but yes, this one is particularly long.
I'm not sure if I will fix these issues because the game is considered finished. Normally, new releases are only to upgrade to the latest version of Solarus or to add translations.

Hmm... the faerie could use a sound effect then, as it gives no response. Either way, if the player has no empty bottle, adjusting it so that it acts accordingly should be rather straightforward.

I have no objection to puzzles. I managed all the puzzles up to that point essentially blind, but that one last block, because it can misalign, and there is no way to fix it, can ruin the completion, and waste a great deal of player time to realise that it's become impossible to solve.

Moving the crystal switch, and the two switch tiles, down 8 pixels might be enough to prevent that; unless it was intentional.  (I would have literally had it on my first attempt, if not for that.)

I'd also say, that  updating to correct any kind of game design problem, would roll into bugs. Then again, I update my projects regularly, no-matter what I change, and always keep older versions available.

[Christopho]

Ok you convinced me, this will be fixed

I have already seen that this message is very helpful to me.