Yeah, the restart button is a problem. The workaround is just to place a small block outside of the play area by just double-clicking.
About the energy - we added it to force players to hit blocks by each other and make the strategy of "putting only wide blocks into a big tower" ineffective. But you are right, it must be more clear what we want from players and what the rules are.
And we need the restart button.
Thanks for playing our game!