From the announcement:
The Mini-Kicker for DeepWars went really well considering it was only two weeks. There were some that could not join in though, while some backers did not have enough time to edit their pledges the way they wanted. We are setting up a "Chip-in" pledge manager to address these issues so backers can now add to their Mini-Kicker pledges and new backers can join in to help unlock some additional miniatures, like the Giant Anglerfish. The "Chip-in" can be found on the AntiMatter site here. All pledges are done through Paypal.