Intrusion [Walkthrough] - Level 3: Hell Express 

Intrusion is a flash Run 'n Gun shooting game created by Newgrounds user "vapgames".
The permission to upload a Playthrough of this game was given by the author.
His channel can be visited here: vapgames.newgro...
You can play this game yourself here: www.newgrounds....
Level 3: Hell Express
Difficulty: Easy
Probably the most annoying enemies you'll encounter here are those elite jetpack using soldiers wielding laser weapons. When they hit you it hurts badly and they take a lot of hits to beat.
The Grenade Launcher which you get from this level on is pretty much the best weapon in this game. It takes out every soldier with one hit but therefor it can also hurt you when you're too close to the enemy.
The Miniboss in this level is another gunship, though this time it's more armed. By just constantly walking from the left to the right and vice versa you will be able to avoid most projectiles it shoots at you. The best strategy is to destroy the missle launcher first and then the giant machinegun.
After that it'll fly away and come back with a "Hammerfall". With both good reflexes and aim you shouldn't have too much problems.
At last you arrive near the end of the train. This mecha ape boss could be considered easier than the miniboss from before. Just shoot everything you have at the boss while constantly moving to the left. You can also try to jump over him but that mostly results in getting hit.