The last few years have seen a glut of Metroidvania titles on just about every platform imaginable. Xeodrifter, Strider, Ori and the Blind Forest, and Guacamelee are just a few notable examples of games that have taken gameplay principles from Metroid and post-Castlevania: Symphony of the Night and applied it with excellent results. Axiom Verge, a game made solely by Tom Happ, is a little different in that it takes more inspiration from Nintendo's space opera than anything else. After about five years of work, the end result is pretty fantastic.

The year is 2005, and you play as Trace, a scientist who's working on an experiment in a facility in New Mexico. As the experiment is taking place, your building collapses, but instead of dying, you wake up in an alien world, and a voice tells you to get a gun and find her. With no clue about what's going on, you obey her request and explore the alien world.

The setup is familiar enough, but the way it unravels is distinct for the genre. For one thing, the full story isn't immediately laid out to you. Progressing through certain spots, like boss fights, will give you the story in fragments, and other fragments are hidden in notes — both translated and not — throughout the environment. Your character's reluctance is noticeable, but he's more bewildered than scared. The environment silently tells its own story. The marriage of biology and machines will be familiar to fans of this game's obvious inspiration, but the look is much darker and with more sinister-looking beings roaming the environments. This isn't a game that's filled with gore, but it does elicit a sense of dread.

From the first few moments, you can tell that it nails down the genre basics. Immediately after obtaining your gun, you're given free reign over the world. You can explore however you wish, but there are roadblocks that prevent you from going further. Things like energy gates, higher levels of elevation, and corrupted terrain prevent you from going down a specific path. The only way to get further into the world is to find a tool to overcome the obstacle, enabling you to progress and uncover previously locked areas. Eventually, you'll reach the end of the game and uncover the whole world, if you're diligent enough.

There are several elements that are needed to make these games work, and it feels like Axiom Verge does a great job of balancing them all. The world is vast, and with so many different roadblocks in your path, the need for new items is great. Fortunately, the game does a great job of drip-feeding you new tools and boosts, so there's always a sense of progression. Power-up availability is done the right way, so you're never starved to find something, but you're also not picking up so many items that it becomes monotonous.

The world is also rife with secrets, including alternate passageways that you can easily miss if you aren't attentive. There are entire areas that are hidden away from the map and have their own sense of progression, so you'll need to return often to uncover blocked areas. It's refreshing since very few games go this far with their hidden areas. Combat is also done well, so enemy patterns are readable enough and don't feel cheap, but even the most common foes can still pose a challenge. Boss fights fall into balanced patterns, so it may take a few tries to figure out what's going on, but you can best any of them once you identify the patterns and play carefully. Later on, the bosses seem to use brute force to intimidate you, but they still don't lose their charm.

One element that places Axiom Verge above the rest is the arsenal. After you find the gun, it isn't too long before you find another firing type that allows you to fire shots and detonate them remotely. You'll soon find things like short-range spread modifications, the ability to shoot homing missiles, a short-range but powerful electric shock, and fire grenades. The weapon arsenal is so large that you're given a radial wheel to swap between gun types, and while you will gravitate toward a subset of these weapons, each has a purpose and will be used at least once.

There's also a very good range of tools to use for exploration. Boosted jumps are somewhat expected, but you also have a grappling hook to help you reach higher spots, and a drill lets you break soft rocks and open new pathways. One of the more interesting tools in your arsenal is a drone that can go through small openings that Trace can't fit through. Equipped with its own energy meter and gun, it's a perfect scout and expands the game's strategic depth.

Of all of the guns and tools at your disposal, the most memorable one is the Address Disruptor. You find this early on, and its sole responsibility is to rewrite parts of corrupted code. Passages blocked by corrupted code become passable once you clear things up, and other corrupted bits can be transformed into solid platforms to access other areas. When you use it against enemies and other moving objects, the results are mostly unpredictable. The slow-moving creature that looks like a blood cell, for example, can become a corrupted mass that destroys blocks to open up passageways. A plant mass that shoots deadly revolving spores will now produce endless amounts of health. Other enemies slow down or have a reduced firing rate and range. Some enemies change their appearance while others are completely unaffected. It feels like the underlying mechanic to Double Fine's Hack 'n Slash, where you have the power to manipulate parts of the world. With such unpredictable results, though, you'll have the most fun entering new areas and using the Address Disruptor just to see what happens.

One thing people may not expect from the title is kindness. Games like this have progressed from being password based to checkpoint based, but they still punish players who don't take the time to save often. Getting caught in a bad boss fight or an unwinnable situation often sends you back to your last known checkpoint and forces you to make up for lost progress. Here, the game saves everything it can almost all of the time. Quitting causes a save, and deaths cause the game to save. You'll still be sent back to the last manual checkpoint, but your progress through the map and items you've collected are retained, saving you from painstakingly repeat actions just because you slipped up. For a game that takes about 15 hours to beat the first time, this is very helpful.

The game also takes a page from its contemporaries by heavily encouraging multiple playthroughs. The ending is weighted toward map and item completion, so unless you have a guide next to you or are extremely thorough, you likely won't see the best ending the first time through. The game also offers a Speedrun mode, which disables all of the story exposition scenes, allowing you to power through the gameplay. The mode also gives you time checkpoints at every boss encounter, so it's easy to chronicle your pace.

If you want to find something wrong with Axiom Verge, you'd have to look very hard or be very nitpicky. The amount of tools and weapons is large but not entirely diverse, as you'll soon grab upgrades for existing weapons instead of entirely new ones. Also, the map is helpful at pointing out the location of save spots and explored areas but not much else. Those who are used to more modern games will balk at the lack of direction and indications, though older gamers might appreciate it, since that's how games were fashioned back then.

Like Shovel Knight, the graphics try to ape their inspiration as much as possible. The pixel graphics share traits with most NES games, so black is used to add shadowing to characters and environments. Your character and the enemies are rather small when compared to what you see in games like Metroid, but they're still rather detailed. Animations are limited but appropriately authentic. Even the corruption looks like what would happen if you encountered it on a classic console, with mismatched colors and characters filling in what would normally be a regular part of the environment. There are a few cheats that remind you the game couldn't have been possible on a real NES. The color palette is deeper, though it isn't quite 16-bit. The shockwave effect from some weapons is also more modern and not retro. Additionally, some of the environments feature different planes of background scrolling, so there's no way this could've been accomplished back then.

That same level of near-authenticity also applies to the sound. There are no voices in the game, and short dull blips take the place of a typewriter sound when characters speak in cut scenes. Every sound effect is also 8-bit authentic, as they're limited in range but clear enough to understand what they're trying to approximate. The range of the music is where the game betrays its 8-bit theme. The dark and brooding soundtrack feels more modern due to the heavy use of bass, but it works so well that few will complain. Each track has a definitive beginning and end, and there's a small period of silence in between, ruining the illusion that older games had of a single looping music track.

In the end, Axiom Verge is an excellent homage to Metroid that also brings some interesting touches to the table. It gets the basics right in terms of giving you a large world to explore with an excellent layout and a nice sense of progression. Multiple boss fights also act as good progress indicators while the story fascinates without overwhelming. The different tools and weapons make the game feel fresh, and the Address Disruptor is the main highlight. Painted with a mostly authentic blend of 8- and 16-bit with a few modern touches here and there, Axiom Verge is the perfect game for those who can't get enough of the genre.

Score: 9.0/10