Ooh yeah the levels get progressively harder to the point where you cannot move as much and your abilities begin to fade away (press the keys a lot of times and it'll still work); that was intentional. It is the player getting weaker and weaker until .... wait that's spoilers. Just spam and memorize the obstacle patterns in your way (I found circling the viruses work to press my lasers enough to eradicate them). I appreciate you pointing out the necessity of feedback to player when enemy is hit; will make note of that for the future. As for falling to the void....yeah that's a bug.
As for the mysterious voice, keep trying the levels to find out who they are! (unless you want me to spoil it; in that case, just reply to me)
Much appreciated for the feedback!