▁the ▁shoot er ▁genre , ▁Space ▁Inv aders ▁was ▁the ▁first ▁fixed ▁shoot er ▁and ▁set ▁the ▁template ▁for ▁the ▁shoot ▁' em ▁up ▁genre . ▁The ▁goal ▁is ▁to ▁defeat ▁wave ▁after ▁wave ▁of ▁desc ending ▁al iens ▁with ▁a ▁hor izont ally ▁moving ▁las er ▁to ▁ear n ▁as ▁many ▁points ▁as ▁possible . ▁ ▁Space ▁Inv aders ▁was ▁an ▁immediate ▁commercial ▁success ; ▁by ▁ 1 9 8 2 , ▁it ▁had ▁gross ed ▁$ 3 . 8   b ill ion , ▁with ▁a ▁net ▁profit ▁of ▁$ 4 5 0   mill ion , ▁making ▁it ▁the ▁best - s elling ▁video ▁game ▁and ▁highest - g ross ing ▁" ent ertain ment ▁product " ▁at ▁the ▁time . ▁Ad just ed ▁for ▁infl ation , ▁the ▁many ▁versions ▁of ▁the ▁game ▁are ▁estimated ▁to ▁have ▁gross ed ▁over ▁$ 1 3 ▁billion ▁in ▁total ▁re venue ▁as ▁of ▁ 2 0 1 6 , ▁making ▁it ▁the ▁highest - g ross ing ▁video ▁game ▁of ▁all ▁time . ▁ ▁Space ▁Inv aders ▁is ▁considered ▁one ▁of ▁the ▁most ▁influ ential ▁video ▁games ▁of ▁all ▁time . ▁It ▁helped ▁expand ▁the ▁video ▁game ▁industry ▁from ▁a ▁novel ty ▁to ▁a ▁global ▁industry , ▁and ▁us her ed ▁in ▁the ▁golden ▁age ▁of ▁ar cade ▁video ▁games . ▁It ▁was ▁the ▁insp iration ▁for ▁numerous ▁video ▁games ▁and ▁game ▁design ers ▁across ▁different ▁gen res , ▁and ▁has ▁been ▁port ed ▁and ▁re - re leased ▁in ▁various ▁forms