I think this is parody of the ending theme to Girls und Panzer, where a couple puns are made.
一緒 (isshou) vs 一生 (issho) 一緒, which I think is used in the ending credits, means "together." 一生 on the other hand indicates "whole life" or "one's entire existence."
かも (kamo) vs カモ (kamo) かも is a particle which indicates the possibility of something. カモ is the word for "duck", and like in English can be used to mean "a sitting duck."
一緒かも --> "Together, we can do it." 一生カモ --> "Forever a sitting duck" or "Your existence is a sitting duck."
Come here ♪Charge into your opponents with all your might ♬Enter, enter ♫Mission ♪Fueeeh...Quicklyyyyyyso that you are a sitting duck!!