Preamble
I can see why this game hasn't been reviewed until recently. It's of such professional calibre that it would take a professional calibre review just to do it justice. I don't know if I'm up to the task, but I hope I can be of some service to this genuine work of art.

Visual: 5/5
This game is beautiful. Glancing at screenshots barely constitutes a teaser. One needs to see it in motion to really appreciate the hard work that went into creating something that flows so smoothly on the eyes.

Every stage in the game is thematically different. Sure, they're all underwater, but you get underwater caves, underwater volcanoes, underwater R-Type bases, underwater Pac Man boards, and so forth. None of the stages are recycled in the 1-1, 1-2, etc style of doing things.
Each stage then brings it's own set of specific enemies, with a few recurrences for the sake of AI predictability. The library of enemies is drawn from probably 50 or more different games, all with the necessary reshading and recoloring to make them compatible with this opulent aquatic universe.

And what may be the most remarkable achievement : The aesthetics aren't overdone in such a way as to impede gameplay. What few overlays there are don't obstruct player vision, and the backgrounds have non-distracting motion, from bobbing plants to harmless NPC critters.
Well, okay, there was that one octo...



Audio: 5/5
I don't think there's any original music on the soundtrack. It's mostly composed of midis anyone can find on VGMusic.com, but everything chosen is perfect for it's part. Quality control was on high alert, avoiding those troublesome different volume and non-repeating track problems that frequent midi using games.

Another notable aspect is the use of a specific BGM for the overworld menu. A very catchy one, no less. I haven't taken breaks from a game to listen to pause music like this since Battletoads on the NES.

And seriously, how many indie games include a sound test? Awww yeeeaaah.
Inexplicably, the songs are labelled "Track 1", "Track 2", and so forth. I'm sure we'd all prefer specifics so we can track down the original music for ourselves, but..... there's disco and an afro so I'm letting this one slide.

Storyline: 5/5
Let's be honest. How much plot can a side-scrolling shooter feature? Is a shmup really the medium for a complex tale of Byzantine power struggle and Shyamalan plot twists?
Instead, Nebulus chooses to exude style over substance. The basic story is as old as the epic of Gilgamesh. The hero, plus companions, must fight the big bad whose threatening the good kingdom and it's princess. Where it goes right is in giving the player a lively and entertaining introductory sequence, acquainting us with key characters while providing a few laughs along the way.

The charm factor of the intro then spills over into the gameplay section, thanks to the clever design of the custom menu system. Just doing basic tasks like checking your progress or Saving will remind you of character quirks and general screwballery. Thanks to that, when you're nearing the end of your quest to collect crystals, keys, prisoners and trophies, you won't have forgotten the original mission or even who XYZ character is.

Gameplay: 4.5/5
There's a bit of an issue with the gameplay.
The player's submarine and enemy creatures move on a pixel basis, whereas hit-detection and your torpedo act on RM2k tile references. You'll be subbing along happily, and your first torpedo shot will launch from the bottom of your sub, while the next one comes from the eyeballs. This causes a lot more misses than the player's own bad aim ever will.

Luckily, it's more of a beginner's problem than anything. Once you begin to flow with it, firing a reference shot when needed, you won't have any concerns. The game's creator was kind enough not to exploit this shortcoming by hammering you with a bunch of swarming mobs where every shot counts.

With learning curve out of the way, the game continues to be challenging without being unforgiving. Level design is smart. The enemies have erratic movement patterns, switch activated pathways force you to think fast, and more than one trap awaits the unsuspecting. Luckily there are 1Ups generously placed throughout each stage, and even if you still run out, the only progress you lose is that particular attempt at beating the level.

Overall: 5/5
This isn't just a technical achievement for the long forgotten RM2k software, but a genuinely fun game. It's the kind that, a year or two after your initial playthrough, you may find yourself going back for another go.....