▁version — that ▁are ▁gradually ▁destroyed ▁from ▁the ▁top ▁and ▁bottom ▁by ▁bl asts ▁from ▁either ▁the ▁al iens ▁or ▁the ▁player . ▁ ▁The ▁player ▁defe ats ▁an ▁al ien ▁and ▁ear ns ▁points ▁by ▁shooting ▁it ▁with ▁the ▁las er ▁can non . ▁As ▁more ▁al iens ▁are ▁defeated , ▁the ▁al iens ' ▁movement ▁and ▁the ▁game ' s ▁music ▁both ▁speed ▁up . ▁De fe ating ▁all ▁the ▁al iens ▁on - screen ▁brings ▁another ▁wave ▁that ▁is ▁more ▁difficult , ▁a ▁loop ▁which ▁can ▁continue ▁end lessly . ▁A ▁special ▁" m yst ery ▁ship " ▁will ▁occasionally ▁move ▁across ▁the ▁top ▁of ▁the ▁screen ▁and ▁award ▁bonus ▁points ▁if ▁destroyed . ▁ ▁The ▁al iens ▁attempt ▁to ▁destroy ▁the ▁player ' s ▁can non ▁by ▁firing ▁at ▁it ▁while ▁they ▁approach ▁the ▁bottom ▁of ▁the ▁screen . ▁If ▁they ▁reach ▁the ▁bottom , ▁the ▁al ien ▁invasion ▁is ▁declared ▁successful ▁and ▁the ▁game ▁ends ▁trag ically ; ▁otherwise , ▁it ▁ends ▁generally ▁if ▁the ▁player ' s ▁last ▁can non ▁is ▁destroyed ▁by ▁the ▁enemy ' s ▁project iles . ▁ ▁Development ▁Space ▁Inv aders ▁was ▁created ▁by ▁Japanese ▁designer ▁Tom oh iro ▁N ish ik ado , ▁who ▁spent ▁a ▁year ▁design ing ▁the ▁game ▁and ▁developing ▁the ▁necessary ▁hardware ▁to ▁produce ▁it . ▁The ▁game ' s ▁insp iration ▁is ▁reported ▁to ▁have ▁come ▁from ▁varying ▁sources , ▁including ▁an ▁adaptation ▁of ▁the ▁mechanical ▁game ▁Space ▁Mon sters ▁released ▁by ▁T ait o ▁in ▁