i need help with game story

[Jereminion]

hello i am making a flash game and i think it needs a story so the player wants to keep going and see what happens. i always show my cousins my ideas before i get dedicated to them but he always says they are bad or not compelling enough for someone to continue playing to see what happens.

if anyone wants to help it is a game like metal slug/contra or some other side scroll shooter.

i want to include cut scenes also to make the story obvious between levels or bosses.

i dont think the game would be good if you are just put into a random world and are sent to kill random people.

if anyone wants to help me think of a story that gives the player an excuse to kill a bunch of soldiers and bosses that would be nice...the bosses will all be mechanical

this is the game so far i am working on the controls and visuals but i cant start on the level until i know what i am doing for the story

http://spamtheweb.com/ul/upload/160410/6 4344_metalslugnew3.php

all i can think of now is an enemy that has a deady virus....because i just saw 12 monkeys on tv...thats how uncreative i am...

[Jereminion]

i got help from http://wolf-raven.newgrounds.com/ this is what im going with so far.....

u are a narcotics officer watching a drug deal. the deal goes wrong and ur partner dies. u call for backup but hop on a vehicle to chase the dealer back to his base. then u kill all the enemies and meet the final boss who just tells u to arrest him and have mercy. just before u are going to kill him someone calls the drug dealer. u pick up the phone and they want to offer his safety for information about other drug dealers around town. the end.

any thoughts?