A claymation horizontal sidescrolling shoot 'em up.
You play as an antiquated spacecraft (the last of the F-27 Platypus fleet) attempting to defend planet Mungola from Colossatropolis (which has become so overcrowded that its inhabitants are taking over Mungola for space and resources). It goes by a Level-Area structure, with 5 Areas in one Level. You get scores depending on the percent of primary targets and transport carriers you kill.
Originally released on PC, followed by PSP, iPhone, and XBLA ports.
There is now a sequel: Platypus II.
Source: Wikipedia, "Platypus (game)", available under the CC-BY-SA License.