All that you can do with them is sell them. That's why they're marked with a dollar sign.
how do you get the jackpot in the prior round, I kept lining up the triple dollar signs but saw no increase of money =/ did it about 4x lined up, then got too fast. on PC, using controller.
edit: crap i shot tentacles left to right, no wonder it didn't work. do I only shoot the 6 lights? can i do it after i kill all the mutants?