How the new Doom patch dramatically improves previously flawed ports

What should have been a beautiful piece of retro fan service didn't quite work out. Last year, fresh ports of the original Doom trilogy arrived across a range of devices and while Panic Button's Doom 3 port hit the target, Nerve's conversions of the original Doom and its sequel left a lot to be desired. Incorrect lighting, broken music, stretched aspect ratios and other issues impacted what should have been a joyous celebration of a genuine gaming phenomenon. However, it's all changed now: while not quite perfect, I can highly recommend these revised ports and in fact, this is one of the most significant game patches I've looked at during my time at Digital Foundry.

To begin, it's worth pointing out that while the new update contains a wealth of new additions and fixes, not every feature is brand new - the game's first patch already managed to correct a selection of the more egregious issues. The incorrect lighting levels in the original release were fixed months ago in the 1.03 update, the mandatory Bethesda.net login requirement was removed and the speed and quality of the audio was also improved. Patch 1.03 basically delivered the game we should have experienced at launch and to be fair, Bethesda could have left things along at the point. However, the decision was taken to further refine it - and this is where things get interesting.

A crucial addition is support for additional WAD content packs. In its current state, both Doom and Doom 2 receive the WADs created for Final Doom while the original Doom also receives John Romero's Sigil with Doom 2 benefitting from Nerve's own No Rest for the Living. This is a huge bonus feature as these additional WADs are all of very high quality, bringing a lot of extra content to the game for no additional cost. According to the patch notes, the team is also curating additional WADs which will become available in due course. While the PC original has no restrictions on what WADs you can run, it's great to see extra content arriving for the console platforms.

Secondly, Nerve has substantially revamped performance on all console platforms. The original Doom engine targeted a half-rate refresh based on a CRT monitor-derived 70Hz, which translates into 35 frames per second locked. This is now running at a silky smooth 60 frames per second. This is a little tricky to explain but while the renderer runs at 60fps, the game logic is still running at 35fps, so there is some level of interpolation built in to the way the game presents - this is how every other source port handles this situation too.

I own Nerve's Doom port on PS4 and Switch, and later picked up the sequel for the Nintendo hybrid. I didn't feel it was necessary to buy every version as the differences are minor, but nevertheless, I did notice some variations in performance that surprised me. Firstly, whether you're on Switch or PS4, the base games perform as expected. Doom 1 and Doom 2 both turn in a stable 60 frames per second with only an occasional blip here or there - at least in the levels I played through. This is small beer, stuff you're highly unlikely to notice or care about.

It's not perfect, but it's very, very close to it but what's interesting is that the add-on WADs can introduce issues. I opted to utilise John Romero's Sigil as a testing point as it's a fairly demanding WAD and sure enough, performance does vary across platforms. On Switch, it's mostly locked to 60fps but you'll encounter a few minor dips here and there. In the grand scheme of things, this amounts to a slight interruption in fluidity so again, it's not really a big deal and something you'll likely never notice.

However, curiously, the base PlayStation 4 version doesn't run Sigil as well as Switch - which is rather odd. Looking closer, it seems that the source port is sensitive to resolution to achieve 60fps, so the resolution is reduced on Switch. While PS4 runs at three times the original resolution at 960x600, the Switch is reduced to 640x400 instead. Thankfully, in a game like this, the reduction in resolution works in tandem with the old-school visual design so reducing pixel counts isn't exactly bothersome but it does explain why performance is faster than the base PS4. As expected, PS4 Pro is essentially flawless.

Next up, there's the addition of a proper 4:3 aspect ratio option. The original port release shipped with a wider 16:10 aspect ratio but this revised release allows you to switch to a proper 4:3 mode, presenting the game and HUD as it should be. It's an improvement but I still have some quibbles with this as both 16:10 and 4:3 modes rely on uneven pixel scaling. Due to the lack of interpolation, pixel width varies across the image leading to slight distortion - and this is happening because your display's native resolution doesn't divide equally into the game's core resolution. I'm not saying that a blur filter is the solution here, but a very subtle sub-pixel interpolation feature could make a huge difference in terms of cleaning up the presentation. It's not too distracting overall but it's still something I'd like to see corrected.

Additionally, I would have enjoyed seeing a proper 16:9 widescreen mode like those available in various source ports on other systems. I understand that the intent was to maintain accuracy to the original presentation but a wider viewing area is a nice feature that would have been worth having. On top of the aspect ratio options you do get in the new patch, Nerve has also added two brightness adjustment options allowing you to change both overall game brightness and map brightness. You can dial in settings that suit your surrounding environment, basically. Playing Doom in a well-lit room on Switch can be difficult at default settings, so these new features very welcome.

Beyond visual tweaks and customisation options, other new features focus on usability. A level select feature is added to the game allowing you to enjoy pistol starts from any map in any WAD. Meanwhile, the weapon selection system is also modified. The d-pad now acts as a quick select for key weapons, which is useful, while toggling through weapons with the shoulder buttons now utilises icons at the top of the screen rather than forcing you to move in turn through every single weapon. Nerve has even returned to the game to change some of the elements which were previously censored. The health packs - which appeared as pills - are changed to a green cross. It's still not the original red cross graphic but it's closer and it looks pretty good. Additionally, the Wolfenstein-inspired bonus stages in Doom 2 have also been properly restored, which is really nice to see.

In fact, pixel scaling aside, I only have one or two outstanding issues. If you utilise your console's sleep mode, the game can exhibit occasional harsh pauses until you close and reopen the game. This is specifically mentioned in the patch notes as improved over prior releases but it's still surprising and disappointing that such a bug remains at all. It's a real problem on a system like the Switch where you're likely to move in and out of sleep mode regularly.

Additionally, I feel as if there is still some extra latency in the controls - especially on Switch. I didn't have a chance to sit down and accurately measure it, but it does feel slightly more sluggish than I'd expect. I know there are multiple approaches to interpolation which can have an impact on input response so perhaps it's related to this? Things could be left as is and I'd still be happy overall, but in an ideal world, I'd like to see a more effective solution.

Still, I don't want to nitpick too much because the fact is that this is a transformative update that sees a disappointing port elevated into a very classy example of great retro fan service. While I prefer sticking with PC source ports and playing at a high frame-rate on my CRT, this is undoubtedly a great way to allow access to Doom on even more devices. It's especially great for Switch owners because a portable Doom experience is always nice to have. It's a big turnaround after some initial disappointment. Honestly, all of the original Doom trilogy ports for the current-gen machines are now no-brainer purchases, especially so for Switch owners. The games are priced well and there's a wealth of content out of the box with more on the way - but ultimately, we're getting new ways to play Doom and that's never a bad thing.