Great Metal Slug style game. With this game you get a health bar and can pick up health and armor, but the stages can be very long, so it can be tough to survive on a single life, which is whats required before you can save your game (in between stage saves). One big challenge is that if you get to the stage boss with just your base gun, it takes a shitload of hits to take down the bosses. You can only fire diagonally with one of the guns, the machine gun. You do have a roll dodge with some I-frames though and the game otherwise controls very well.
I completed the first stage here and also did some save state practice on Stage 2, after failing it normally. This shows how I learn these games and put them together. I still have to practice the second boss more, or just get there with better weapons.