i am trying to get this achievement, but it doesn't unlock when i spend all the energy during the battle. or whether do i need to finish the final mission with zero energy?

Am I missing something here? When I was first hiring new agents to go on the initial mission, I couldn't find a way to back out of the interview once it had started, and the only dialogue option at the end was to hire. Is this a glitch? A temporary mechanic? It's frustrating....

I saw another Twilight Wars which has multiple language support.

Started the game, came to a screen with some faces and flickering screen-like animations and an hourglass in the lower right corner. Couldn't do anything. Had to kill the process to get out. Not cool. Edit: Turns out it was just a horribly long load time. Still not cool, but at least it's not a soft-lock. At the end of the demo the only options are to Wishlist or answer a poll, there is no exit, even after I answered the poll. Definitely needs some work....

After playing the demo I think I should say that you need to remove the energy use on abilities. I failed my first run simply because I used energy-based abilities twice, then ran out of energy (used the battery I bought, never got another one). Tying down both movement and ability to one resource is a horrible design idea....