I swear I managed to get this animated sprite thing to work once before, but I'm using Blockly to import an existing B&W sprite that is 60x40 pix, with the intent that it be loaded as 2 frames (30x40 pix). It is acting all kinds of crazy when displayed, splitting the image vertically also and repeating chucks within the "frame". It's hard to tell really what's happening, but I know there's nothing in the Blockly side of things that seems to have any control over this.

Was there an update that's changed how Blockly imports sprites?

I swear I managed to get this animated sprite thing to work once before, but I'm using Blockly to import an existing B&W sprite that is 60x40 pix, with the intent that it be loaded as 2 frames (30x40 pix). It is acting all kinds of crazy when displayed, splitting the image vertically also and repeating chucks within the "frame". It's hard to tell really what's happening, but I know there's nothing in the Blockly side of things that seems to have any control over this.

Was there an update that's changed how Blockly imports sprites?

We were made aware of this issue in our Discord. I am currently working on a fix. I will update the Thumby Blockly tutorial when everything is ready to go.

I be sure to let you know.

 I added a new block with a little documentation of it here: https://thumby.us/Blockly/Making-Sprites/#drawing-animated-sprites

Hopefully that fixes your problem.