Well made game. I like the graphics. I like the way you made goals that get more difficult as you go on. I failed the first few times not understanding what is going on because the instructions were unclear. Once I realized that I had to get the exactly correct value for healing, it made sense what the game was about and became more fun. The sound is pretty good. The way things move are pretty satisfying. Deletion felt wrong and it wasn't immediately obvious what the energy costs were. Solid.
I love the gameplay, super fun, it's harder than it looks! The only reason I wouldn't give it a five right now, is because of the awkward movement and firing mechanics on two levels: 1) I don't think the movement and firing should be on the same event, and 2) the movement is awkward with clicking and where the player ends up are proportionate, but it doesn't quite feel right, and feels like I'm never sure of the player's destination when I click, same with firing, never sure that I'm clicking on a target, so maybe also add some hover over to the targets to indicate firing on that target is now possible with the click. Also, some kind of indicator to go with movement would be the way to go as well. Please keep working on this, as it's wonderful!