It was originally unlimited ammo, but it felt too OP and you could just camp by the transporter. I wanted to add a way to force the player away and leave it open to attack, hence the ammo pickups.
I really had Blast Corps in mind as my initial idea before i started development, I liked the idea that you have no control over the transporter, you just have to clear the way to let them progress. With more time I would have added more content to stretch the gameplay out more.
Thanks for playing and for the feedback, i hope you enjoyed it