Fun concept, I had a good time playing. Early on I worried a bit that I might get bored, but it held my attention. I imagine there’s a lot of room for creative things you could do to expand on the idea if you chose to develop this further; various unlocks hidden around the map, build zones in different places requiring transporting items, prebuilt machines in fixed positions around the map, etc.
I’m guessing the “can’t lift items higher than 1 block” is a measure to prevent an exploit where you could feed the same item through a 2x machine repeatedly, making completing the game trivial?
But the exploit is currently possible anyway, since at time of writing the way it works is “you can’t lift an item more than 1 block from the position you picked it up at”, meaning you can build a “staircase” of extra items and carry your target item up half a block at a time. (I tried this on a new run to test, and of course easily hit the goal with a single ~1e16 item a couple minutes after unlocking the 2x machine)
An alternate solution here might be to render “raw” items you mine differently than “refined” items that come out of machines (different shape and/or color?), only allow the player to pick up “raw” items (removing the height lift limit), and tweak the physics of refined items so that they can’t be lifted by raw items or otherwise physics’d upwards.