I have a few suggestions/ideas. Some might be outside the limitations of the game, but just some thoughts I had while playing:
-power tool versions of axe/saw and hammer (similar to mining drill)
-propeller pack tweaks (seems a tad OP to only have condition and not require fuel, folding up when not in use, different key to disable)
-half blocks (they would need to take up the full block size-wise, but having just a slight height would be nice for decorative touches, like lining paths)
-larger doors/gates (double doors, 2-story height doors, etc)
-holding down the mouse to continuously pick up items (vs clicking for each one)
-animal husbandry/ability to interact with the other animals (could be irrelevant depending on how pets are going to be implemented)
-horse carts or saddle bags
-offroad vehicles (as it stands, cars don't seem to be overly viable in Explore without clearing objects out of the way, could just an alternative to horses)
-collection/placement of water (I know this one could be VERY tricky, but just an idea for an ability to create ponds)
-more electricity items (light sensor, rotating light [for lighthouses])
-tree taps (for rubber/resin- could be a slow way to collect resources without cutting down trees)
-crafting stats/clarity (being able to know the size of the block/how many are crafted BEFORE being crafted. stairs for example, I had no idea crafted in 5s, and MANY times I've made the M sized blocks instead of small) <- I'm assuming this was touched on in the crafting/inventory UI portion
-some sort of despawn timer (having items laying all about around the world is taxing on performance)
Again, just some ideas. I know most of them are kind of out there, and definitely not necessary. My biggest gripes seem to be covered already, so keep up the good work!