The screen below may not mean much, but it's a slight turn in a new direction. Currently the player has a set number of lives, along with the collection of extra lives via placements on the map. As it stands, it's pretty simple, and straightforward. To give the game a bit more ummf.. I have expanded on the theme of "brains" through out the game. Considering you and your foes are advanced cybernetic AI robots with human brains, and the story is based on the use of human brains... I added brain drops on the enemies.
Kill an enemy, enemy drops a brain - player collects.
If you die, brains are emitted (similar to sonic's rings) and the game is over. If you beat a level, without dying of course, you advance further in the game adding to the "Saved Brains" total from the collected brains from each level. The fun part is that after collecting X number of brains, you will be able to buy extra lives to overcome perma-death. In contrast if you don't purchase lives with the brains you have collected and continue to advance, you can loose ALL of your save brains and die. I still have a bit of testing to do, to see if this method works well as the game increases in difficulty.
Update - EDIT
Yay! Testing successful! Extra lives based on brain collection. In this case you need 50 brains to get extra life. (which has been rewarded previously on last scoring round)
Brains collected = brains collected at level completion
Brains Saved = Total brains left before extra life reward