To start: I used to add a longer header to these reviews, but since it often made the reviews too long to submit, I've opted to leave it on my Backloggery. Shouldn't happen for this game, but I am nothing if not (mostly) consistent.
Gameplay: On its surface, Mutant Mudds doesn't seem too impressive. It's an indie platformer in the vein of the NES games which inspired it. After playing it through, I can definitely agree with the sentiment that the game isn't too particularly impressive. However, this game does manage to be a good bit of fun, with a surprising bit of challenge in some of the hidden levels, albeit also with a rather wonky difficulty curve.
This game is best described as a level-centric Metroidvania-lite. There's four levels per "world" and five worlds total; twice that if you count the alternate stages for these. Within these stages are hidden stages which are unlockable via the three powerups you collect throughout the game: a powerup that lets you hover for longer; a powerup that allows your shots to break down barriers (not doing any additional damage to enemies, oddly enough), and a powerup that lets you jump much higher than initially. You can only hold one of these powerups at a time, but there are secret characters which you can unlock that have all three at one time. These characters are used to unlock CGA stages, a more difficult series of levels which are used mainly for completion's sake and nothing else. This game is also something of a collect-a-thon, albeit a very mild one. There are 100 collectables per stage, amounting to 4,000 by the game's end. These aren't hidden in particularly challenging places, but they do force you to do some precarious jumps from time to time.
The main gimmick of the game is that there are three planes of stages. One thing that I learned was that this game was a port of the 3DS version, and after learning that, I can see exactly where the gimmick came from. While I don't own a 3DS and as such can't say for myself as to how good the 3D effect is, I can say that the game does an okay job of recreating that feeling of depth, even if some elements of the foreground do get in the way from time to time. It's not a dealbreaker, however. As for the stages themselves, they're fairly "rompy." I really can't think of any other way to describe them. There's no boss battles in this game, which rather surprised me considering that a boss fight could work with the control scheme, but again, it's not a big deal. My biggest complaint about the controls (and is a complaint shared by many others) is that movement is very sluggish and can potentially lead to a somewhat boring experience. I do wish your character moved faster, but that would also require changing a lot of the stage design.
At the end of the day, Mutant Mudds Deluxe isn't out to blow the hinges off of anyone's door. What it instead intends to do is give you a pretty good time. It did only take me just over five hours to 100% the game, and almost exactly the same amount of time for a person who is much better at platformers than me to 100% the game. Beyond that, I don't see much in the way of replay value. I don't know if I'll ever be coming back to this game, to be quite frank. I did have a good time, though, and I do feel like I got my $10 of value. 7/10.
Story: Nothing remarkable; I'll be skipping to Graphics.
Graphics: When you start the game, it launches in a window... with menus. In fact, things like screen resolution and control configuration aren't actually baked into the game, meaning that if you wanna change controls, you'll have to go into windowed mode in order to change your settings. A bit disappointing, but that would mainly be a niche issue if you ask me. Once you get that business sorted out, the game doesn't have any graphical issues whatsoever. As for the art design, it reminds me quite a bit of Wonder Boy's graphics. It of course comes down to how you feel about pixel art, but for my eyes, the game wasn't that bad. Animations are smooth, there's pretty good shading on the enemies, and it all has a pretty nice style. Good stuff all around. 4/5.
Sound: Again, this comes somewhat down to taste, as the soundtrack for this game is entirely chiptune music. It's not bad, but I don't really remember much of it, even after having just played it. As for the sound design, it's just some bleeps and bloops. Not really worth discussing all that much. Of course, there's no voice acting either, but did you really expect it? Pretty alright and nothing more on this front. 3/5.
Overall scores are: 7/0/4/3; cumulative score of 7.0/10. It's just a fun, simple little platformer that doesn't go too far beyond being fun or simple.