A played a few minutes, here are my thoughts:

1. Starting menu, UI and graphics is nice in style and presentation, well done.
2. The tutorial explains mechanics clear enough, I did not have any trouble with understanding.
3. Since this is obviously 'Plants vs Zombies' with a twist, I will make a few comparisons.
4. The 'need energy always' trick is interesting and original in principle, but see below.
5. The gameplay is *very* stressful compared to PvZ, the need for constant switching makes the game much harder and requires vigilant attention to hard-to-see details (i.e. which exact lanes need switching on/off. For me personally, this effect made me tired at level 3(!) especially since the difficulty seems to ramp relatively quickly.
6. I would suggest altering the UI to make it *much* easier to see what is going on
   1. highlight on/off state of robots much more prominently, something like full recolor to red/grey.
   2. highlight the lane under cursor
   3. highlight the 'wrong state' robots, i.e. turned on then there are no enemies and turned off then there are.
   4. indicate drain vs income of energy very clearly (something like green/red parallel bars), so player can see at a glance how many panels he needs and how many robots he may afford
   5. reduce the number of lanes in starting stages, use it as part of a difficulty ramp
   6. add 'active pause', at least as a global 'easy mode' option
   7. recolor part of the timebar instead of using just an arrow to indicate current time
7. I understand that this is probably just 'not done yet', but make it possible to continue game from the point I left, not from the beginning.

Good luck with your project!