Neat little game, I also really enjoyed the art style.
For the most part I stayed in the bottom part of the ship, charging the three batteries and using them on the lower engine, until one of the batteries clipped into a wall... I think there should be something to force you to actually use the different engines/chargers. Maybe the engines overheat when you use them over and over or the charger on the ceiling charges the batteries more/faster. Stuff like that.
Being able to throw the batteries around would also be a neat addition, I think. With the reticle it felt that was something you'd be able to do but the batteries were always dropped at my feet.
Overall very well done for a first LD entry though! :)