This Atari 2600 homebrew port of Boulder Dash was first revealed in 2011 and there was talk of releasing it as a cartridge, but I’m not 100% sure if that actually happened or not (I think it did, from what I can see online).
The only ROMs available online are a two-level demo made by the developers to show off the game, and that is what these screenshots are from.
The King of Grabs 