CARGO is one of the four daily puzzles in NOCTURNE ISLAND, a small browser game I'm making on my own.

You get a ship's hold with a few blocked cells and ten crates of different shapes. Crates can't be rotated. The hold can be filled completely, but only with some of the crates, so a big part of it is working out which ones stay on the dock. Your score is how much of the hold you filled, and you lock it in with Finish loading, so a partial load still counts.

Each day's hold is generated with a known full solution, and everyone gets the same one. The other three puzzles are TANDEM (one arrow moves two couriers), BLOOM (water every greenhouse bed exactly) and RANGE (trivia answered with a range).

Free, no account, works on phone and desktop. Two things I'd like to know: does it become clear early enough that you're not meant to use every crate, and does dragging feel okay on a phone?

One of the four daily puzzles in my browser game is TANDEM. It's a 6×5 grid, and one arrow press moves two couriers at once. A courier that hits a wall or the edge stays put, and if both would land on the same cell or swap places, neither moves. You have to get both onto their goals.

Hand-placed goals tend to give levels that are either trivial or have a silly 3-move shortcut, so the generator works the other way round:

1. Seeded RNG from the date, then place 7–9 walls and reject the layout if the open cells aren't connected.
2. Pick two start cells.
3. BFS over the pair state (cell A, cell B). That's only 30×30 = 900 states, so a full search from the start is basically free.
4. From everything reachable, keep only pairs whose shortest path is 9–15 moves and where both couriers end up off their start cells. Pick one of those as the goals.
5. Par is simply the BFS distance, so the "optimal" score is exact and not a guess.

Because the goals come out of the search, every puzzle is solvable by construction, and difficulty is controlled by one number (path length) instead of my intuition. The weak spot: path length isn't the same thing as perceived difficulty. Some 10-move layouts feel harder than 14-move ones because the trick is moving "into" a wall on purpose so only one courier moves. One idea is to also count how many of the optimal moves are those one-courier-blocked moves.

If you've done generate-then-filter for puzzles, what did you end up measuring for difficulty?

The game is NOCTURNE ISLAND (four small daily puzzles, same set for everyone, free, no sign-up): https://nocturne-island.com/

I've been building a small daily puzzle game set on a moonlit pixel island. There are four short puzzles each day: RANGE is trivia where you answer with a numeric range (the tighter the range, the more points, but a miss scores zero), TANDEM is a grid where one arrow moves two robots at once, CARGO has you pack oddly shaped crates into a ship's hold, and BLOOM is about giving every greenhouse bed exactly the water it needs.

Everyone gets the same set, new puzzles come at midnight UTC, and it's free with no sign-up. I'd really like to hear which one feels too easy, too fiddly or just unclear.

(Link: https://nocturne-island.com/)