Well this is a bit of a downer. Metal Slug 4 is the first entry not made by the original team at SNK, instead being helmed by MEGA and Noise Factory (who made the music of the last few Metal Slugs). And it shows. This game is a far cry from the fun as hell Metal Slug 3, which is impressive since it looks the exact same. The level and enemy design just ain't there. It's difficult without being that fun.

Remember the lil narrative bits from 1, 2/X, and 3? Well those have been toned down, this time telling of a reformed Rebel Army. The most we get is an opening cutscene and a twist during the final level. Each level also ends by Eri and Tarma from the last few games taking you to the next level. In their stead, you can play as Nadia and Trevor. While I do miss Eri and Tarma, I can't lie, Nadia and Trevor are really cool.

Now I've been a bit of downer in this review, but it's not all bad. The gameplay is still good, after all, it's still Metal Slug. Plus the final level is actually kinda good (and the music kicks ass).

A long time ago Roger Ebert wrote a review for the first Resident Evil movie, in which there's a deadly laser trap in a corridor that speeds down at the characters first in individual rays, then in groups of two or so, and finally in an unavoidable mesh that covers the whole corridor, and mentions that this is the first time he's ever seen "a security system with a sense of humor." I thought about that bit while I was fighting the last boss in this game, for which I duly removed a whole star from my rating.

Metal slug 4 is the fifth game instalment in the Metal slug series, and no, you don’t have to play any of the previous ones. At its core, the series is a 2D run-and-gun shooter, that has a more humorous approach to the military shooter genre. Metal slug 4 is more of the same. It neither has any innovation nor changes anything to the formula. While that would be fine for anyone who really enjoyed the previous titles, personally I was starting to get a bit bored, thus the lower rating.

Story
There is no story in the game. I don’t count anything that is outside the actual game. However, all the characters, enemies and allies, have a lot of personality simply due to their animations.

Mechanics and gameplay
If you have ever played any 2D game before, you will easily get the hang of the controls. It should be noted that auto fire is turned off by default. I was able to enable it in the settings.
You always start with the standard pistol and a few grenades. Thought the level, there are special weapons that are much more effective, although they have limited ammo. The most powerful weapons are the various vehicles. They are not only able to dispatch foes much faster, but they can also take damage.
Yeah, in Metal Slug if you get hit you die and one of your 3 lives gets used up. Since this was originally an arcade game, where higher difficulty meant more money, Metal Slug pulls no punches. There is however salvation, when your 3 lives are up you get the option to completely trivialize the game and just respawn at no cost.
I am a bit disappointed in the enemy and level variety. The last game had aliens, ancient ruins and while this focused more on robots, there wasn’t anything that grabbed my attention.

Graphics and artstyle
The artstyle is as always incredible. I believe all the sprites are hand drawn, which explains why they are so vibrant and full of life. Metal slug is the kind of series that manages to put more character in a low-level grunt, than most AAA games have in their protagonist.

Atmosphere
It’s an arcade game, so there is hardly any immersion.

Soundtrack and sound effects
SFX are great. You will always know when something dies.
The soundtrack is phenomenal. If there is one thing that you should take away from this review is that you should listen to the Metal slug 4 ost, in fact listen to all of them. Favourite part is “Secret place [stage 6]”.

Final Thoughts
Yes, I am a Marco main. How could you tell?

"Metal Slug 4" isn't necessarily a bad game. I'd even say the core run-and-gun combat of the series manic nature is just as intact here as it's been in the past. Where the game fails though, is its lack of any discernable factor that sets it apart from the previous games. Most of the signature set piece events are gone or not nearly as memorable. It also suffers from a very inconsistent frame-rate. In short, this just feels like going thru the motions. I'd even go so far as to say, comparatively to the games before it, this one comes off as directionless and dull.

A fairly miserable sequel to Metal Slug that had unfortunate circumstances. I mean, how on earth can ANY development team even dream of living up to a game like Metal Slug 3? But even so, this game lacked any real creativity within what they had to work with, and most enemy spawns have this incessant need to be tedious, as some screens take what feels like hours to finish.

There's also the matter of presentation, which is also pretty awful. Most sprites are completely recycled/frankenstein'd together from the previous games, and the music just isn't that exciting nor game-y. Also, both of the new characters have knacks that make them both worse to play, not sure what made them think that was a good idea.

It's worth going through once out of sheer curiosity, but I doubt most would really be that compelled to replay it. I'm convinced anyone that views this game in a brighter light than I probably never played any of the Metal Slug titles before this.

Depois do 2 é dificil dizer o que é um Metal Slug meh, todos os jogos são iguais, só alguns mais simples do que os outros, e o 4 cai exatamente nesse ponto.

É um jogo muito simples e sem graça na segunda metade, mas começa BEM DEMAIS. Única coisa de realmente marcante dele é a trilha, até o momento a melhor da franquia, uma pena que não utilizaram o motif dos 3 jogos anteriores.

Ainda assim, Metal Slug 4 é sem graça, mas um bom jogo.

Entre todos os Metal Slug's principais o 4 é oque eu achei o mais fraco.

Depois de jogar o 1,2X e 3 era esperado do 4 ser tão bom quanto os anteriores porem ele acaba sendo um jogo muito simples que joga seguro e não tenta algo absurdo como o 2 e o 3 fizeram, todos os inimigos, fases e chefes são bem simples e não tem muita coisa que se destaca ou chama a atenção.

O boss final acaba sendo o mais paia da franquia e zerar o jogo me deu uma sensação de que o jogo estava muito inacabado.

Ele não é um jogo ruim, porem ele não faz nada excepcional, só fica no mediano mesmo.

Tentaram inovar neste.

Não é tão caótico e único quanto seus antecessores

O level design é bem fraco

Mas eu gosto do trevor e da nadia me julguem.

Soundtrack maravilhosa como sempre, apaixonado na música da primeira missão.

Also amo a capa desse jogo.

After suffering from a bankruptcy, SNK had replaced the original Metal Slug team with a new one, and this is their first game.

Overall, it's decent at best. Main issues are the large amount of reused assets, even for a Metal Slug game (5/6 bosses are a Frankenstein made of pre-existing sprites) and the level design is a bit lacking.

Still though, I can somewhat forgive all of this, as SNK was coming back from a bankruptcy with this game.