Goodbye doesn't always have to be the saddest word – it can be explosive, too. Resogun: Defenders marks the last of the post-launch expansions for Housemarque's critically acclaimed PlayStation 4 shoot-'em-up, and, perhaps unsurprisingly, it's something of a humdinger. Packing two brand new modes – Protector and Commando – the Finnish outfit is in fine form yet again, as this is some of the most fun that you'll find on Sony's next-gen machine.

The first of the two additions, Protector, distils the very essence of the release's homo sapiens saving affair into a non-stop adrenaline rush. Set inside a single, rotating arena, you'll need to blast your way through hordes of voxel-based adversaries in search of humans, which you'll then have to transport back to your base. It sounds similar – and it is – but the twist is that you're tasked with building up a city this time, which larger crafts will try to destroy.

As you progress, you'll unlock the ability to carry more people at once, which means that you'll be taking risky dashes away from your haven in order to gather up as many hostages as possible. The pace of this option is much faster than the core game – your Overdrive and Boost metres recharge much quicker – which gives it a real frantic feel. There are also Super Boost and Super Overdrive tokens to collect, amping up the action to the next level yet again.

It's all beautifully poised, too, which augments it with that all-important 'one more go' appeal. Making a drop will reward you with various power-ups, so you'll constantly be on the edge of your seat as you rush through waves of enemies back to base. Environmental hazards – such as erupting volcanoes – layer a bit of visual interest on top, and the scene transitions – which occur each time that you complete a city – make this the best looking mode so far.

Not that Commando is aesthetically uninteresting either. This is perhaps the biggest departure for the release so far – even more so than the previous add-on's enjoyable Demolition option – as it puts you in the neon suit of a Schwarzenegger-esque survivor, and tasks you with protecting your home from asteroids and enemies. Rather than control a ship around cylindrical stages, you'll instead be working in a limited area Space Invaders style, firing at objects falling from above.

The core controls remain largely unchanged, but you do have the ability to leap, which adds an extra layer of challenge, as some foes can only be taken out from behind. It's also possible to increase points bonuses by plucking tokens out of the air, which encourages risk taking, but rewards with big multipliers – and by making you feel like a bad ass. New power-ups, such as an outrageous minigun, round out the mode, and keep things feeling fresh.

Of course, we'd be remiss to overlook the Challengers update which launched alongside the premium expansion pack. Adding some light role-playing mechanics into the mix, the free patch essentially sprinkles a progression system on top of the title's uber-tight action. Completing feats – such as rescuing a cumulative number of humans or scoring a set number of points – will reward you with XP, which will ultimately enable you to level up. Hitting certain ranks will unlock additional Challenges, which tweak the game's rules slightly, and offer additional incentive to keep playing.

These can be tackled both online and offline, while Weekly Challenges rotate every seven days, and provide another set of scoreboards for you to conquer. Again, these employ adapted rules, such as the current objective, which sees you attempting to set a top score on one of the original stages – all while using the 360-degree firing Super Stardust ship. It's these little tweaks that make the release almost impossible to put down. Oh, and there's a pretty excellent photo mode, as well.

Conclusion

Resogun: Defenders signs Housemarque's shooter off in predictably sublime style. Protector is arguably the game's greatest mode to date, offering everything that's enjoyable about the original – just at pulsating pace. Commando's not quite as successful, but it delivers an imaginitive twist on the existing formula, all with plenty of personality and panache. This is still, in this author's opinion, the PS4's best original game – and the frightening thing for other developers is that it just got better again.