• ✓Nothing here can be wrong, and that is the design rather than a shortcut: the child decides what belongs, how big it is and where it stands, and the moment any of it is scored it stops being theirs
• ✓What it builds is composition and a story: a whale in the meadow is a decision rather than a mistake, and the child who put it there usually has a reason they want to tell you
• ✓Tap to add, drag to move — a tap drops the thing into the middle of the scene, so a child who cannot yet aim a drag still gets their whale into the meadow
• ✓The selected thing gets a toolbar rather than a gesture: pinch-to-resize is lovely and is also unusable by a four-year-old with one finger, so bigger, smaller, turn-round and take-out are real tap targets
• ✓The last thing placed is the one on top, which is the rule everybody already knows from putting real stickers on real paper
• ✓Eight nudges that exist to be ignored — “make it night-time”, “put in one thing that should not be there at all, then think up a reason for it” — and not one of them has a right answer
• ✓Not one new picture: the eight places are painted stage plates already on disk, and all 66 stickers are cut-outs from the 153-item vocabulary set
• ✓The verifier checks every file really exists and refuses to let one thing sit in two drawers — a drawer with a hole in it is a row of broken images
• ✓Play-tested at 390px: placing, dragging, resizing and removing all work, the work survives a change of place, and there are no broken images, no overflow and no console errors

✓ = done · ☐ = planned. Every game is built one step at a time like this.