My sprite falls through the floor

You press Play and the hero drops straight through the ground and off the bottom of the level.

Check these first

  1. Is the floor solid? Click the floor. In the Properties panel, Is it solid? must be Solid (blocks everything) or Platform (jump up through it). Just decoration stops nothing.
  2. Is the floor a sprite? Sprites are never solid. The floor must be a Block, a tile from the library, or a background. Delete the sprite floor and add Grass from + Add object โ†’ Library.
  3. Is the floor on a hidden layer? In the Layers panel, a layer with โ—Œ is hidden. Hidden layers are left out of the game. Click it to show the layer.
  4. Is the hero already inside the floor? A sprite that starts overlapping the floor can slip through. Nudge it up with the arrow keys until it sits on top.
  5. Is gravity very strong? A high Gravity strength can push a fast faller through a thin floor. Make the floor thicker, or turn the slider down.
  6. Is there a gap? Tick Snap to grid and look along the floor for a missing tile.
NutHouse
A floor Block selected with Is it solid? set to Solid

Why it happens

NutHouse only treats tiles, Blocks and backgrounds as ground, and only when their Is it solid? setting says so. A sprite with a picture of grass is still a sprite, so the hero passes through it. Hidden layers are left out of the game entirely, so a floor on a hidden layer is the same as no floor.

Still stuck?

Try the Chocobreak tutorial, open a sample game and read its rules, or look at the questions people ask.