I have it programmed to where the more enemies you destroy, the faster the power drains. So in some cases it is faster to attack enemies than wait to die.
Even if you already did that, I do feel I tuned it to be too forgiving especially based on the extra power you got. Maybe respawns should be more expensive or max power should be capped at 50. There was an unbelievable amount of variables to tune, and with some more time I could've made it more challenging near the end.
Thanks for the feedback!