Thanks for trying out the game.
Yes the metal balls do give you extra tiles and as for the second jump, you can remove your previously placed tiles to reuse them (The "X Remove" button bottom left in build menu ) . Sorry for the lack of tutorial/ introduction to game mechanics.
Its was a last minute idea so the game loop is kinda messed up lol, you can practically finish the "level" by just 2 tiles if you keep building and replacing. Should have planned out more.
Guess that's a lesson for future updates or the next game I make.