▁levels , ▁players ▁can ▁purchase ▁weapons ▁and ▁devices ▁for ▁their ▁ship , ▁and ▁upgrade ▁them , ▁provided ▁they ▁have ▁enough ▁money . ▁ ▁However , ▁J ets ' n ' G uns ▁is ▁more ▁complex ▁than ▁Ty rian ▁in ▁this ▁respect . ▁There ▁are ▁many ▁more ▁weapons ▁to ▁choose ▁from , ▁a ▁greater ▁variety ▁of ▁devices ▁to ▁purchase ▁and ▁more ▁ways ▁to ▁upgrade ▁the ▁player ' s ▁ship . ▁Also , ▁unlike ▁in ▁Ty rian , ▁where ▁a ▁player ▁could ▁get ▁through ▁most , ▁if ▁not ▁all ▁of ▁the ▁game ▁using ▁the ▁weapons ▁available ▁at ▁the ▁start ▁of ▁the ▁game ▁( with ▁up gr ades ▁and ▁new ▁ship ▁systems ), ▁in ▁J n G ▁the ▁player ▁is ▁forced ▁to ▁experiment ▁with ▁their ▁weapons ▁in ▁order ▁to ▁be ▁successful . ▁The ▁game ▁has ▁no ▁lives , ▁so ▁the ▁player ▁can ▁keep ▁attempting ▁a ▁level ▁until ▁they ▁beat ▁it . ▁ ▁According ▁to ▁the ▁developers , ▁one ▁of ▁the ▁reasons ▁they ▁chose ▁to ▁do ▁a ▁side ▁sc roller , ▁as ▁opposed ▁to ▁a ▁vertical ▁sc roller , ▁was ▁so ▁they ▁could ▁put ▁in ▁lots ▁of ▁visual ▁hum our . ▁Play ers ▁can ▁expect ▁to ▁see , ▁among ▁other ▁things , ▁space fig h ters ▁with ▁kn ives ▁stra pped ▁to ▁them ▁and ▁various ▁hum orous ▁signs . ▁They ▁can ▁also ▁expect ▁most ▁of ▁the ▁weapons ▁in ▁the ▁weapon ▁shop ▁have ▁advert ising ▁post ers , ▁emb la zon ed ▁with ▁messages ▁such ▁as ▁" U lt imate ▁destruct ive ▁power !" ▁or ▁" As ▁seen