Freespace 2 remains one of the best space combat sims around thanks to its dedicated modding scene, mostly centred around the Hard Light Productions forums. Fans have been polishing up and fine-tuning Volition's old workhorse for nearly two decades, and have been exceptionally organised about it. Your one-stop shop for space dogfights is now Knossos, a fan-made launcher app just for Freespace 2 mods and free standalone fan-games. Here's some the best that you can play today, plus a quick guide on where to start for absolute rookies and old aces alike.
To play Freespace 2 upgraded with shiny new 3D models, nicer effects and remastered cutscenes and music, you need just two things: A copy of Freespace 2 (from GOG or Steam), and Knossos. If you have the GOG version of the game, you don't even need to install it. When you first set up Knossos, it'll ask for the installer location, and extract any files from it as needed - it's a rather clever piece of software.
All there's left to do after that is launch Knossos, go to the Explore tab, and grab 'MediaVPs' - a dry name for a great HD overhaul. Tick any and all boxes when prompted to get every upgrade. Switch over to the Home tab and click 'play' on MediaVPs, and away you go. Some more old-school space-aces may disagree, but I've two things to say about Freespace 2 that may help new players:
1. In my opinion, it's far easier to aim and shoot with mouse and keyboard than a joystick, especially when intercepting torpedoes and bombs, which you'll be doing a lot. Some folks are great with other controllers and more power to them, but when I need to fire pinpoint shots at distant pixels in a hurry, mouse is the only option for me.
2. The default control scheme is a mess. Make like Marie Kondo and clear out the clutter - don't be afraid to just delete every binding (F2 opens up the options menu mid-mission) and add controls as you need them. What worked best for me is an FPS-like control scheme centred around the WASD keys, with basic targeting and weapon switching buttons closest.
Between the visual upgrades and fiddling with the controls to get a more modern layout, Freespace 2 holds up really well, and has some surprisingly quotable dialogue and battle-chatter. Some of those old effects still hold up to this day, like beam weaponry punching clean through a capital ship's hull and out the other side.
Knossos is packed to the gills with enormous new campaigns for Freespace 2, but Blue Planet is the closest, I feel, that modders have come to producing a proper sequel. Its creators hope to some day finish the story, and only the first two of three acts are voice-acted at present, but there's an enormous amount to chew on despite that, including a decently written story, a diverse cast of characters and over fifty missions. The final battles of each chapter are gruelling, but spectacular. A modern PC should have no trouble with them, but when Blue Planet's first iteration released over a decade ago (it has since been remastered), it pushed most machines a bit too hard.
While some of its story choices (such as the new mysterious alien race) are divisive, the new ships and factions help to spice up the combat a lot, and there are some spectacular battles to be had once the new Terran forces get involved. Their ships are vastly more detailed than anything in the original game, full of moving parts to ogle as you fly by. If there's one campaign I'd absolutely recommend playing after Freespace 2, it's this one; some other projects such as Wing Commander Saga might have slightly higher production values, but this stands well as a successor to the original.
Intriguingly, Blue Planet also includes an 'enhanced' and rebalanced version of the Freespace 2 campaign. It's not something I've delved into beyond the first couple of missions, but if there's any crew I'd trust at this point to improve on the original campaign -- even if it is only minor mission tweaks -- it's this one. If nothing else, it uses Blue Planet's slightly improved HUD (it places the dialogue box closer to the centre, making it far more readable).
Wings Of Dawn (Standalone)
This is a recent standalone release, with no Freespace 2 needed -- just download it via Knossos, and go. Wings Of Dawn is pretty dang anime, even going so far as to have visual novel style dialogue sequences, with an optional '18+' pack adding some largely pointless nudity. Anime space battles are always cool, though, and from the ship designs to the sound effects and music, there's a lot of bombastic, melodramatic energy to this game. Once you start getting into larger battles, it's often tempting to just hang back and watch the fireworks. Freespace needs a replay viewer, Ace Combat style.
Wings Of Dawn's combat is demanding but often clever. One of the earliest missions sets the tone, with you luring an enemy capital ship into range of explosive containers to try and slow it down, all the while juggling interception of fighter and bomber wings. This would be a lot easier to juggle if the mod had voice acting, but you'll have to split your attention between the action and reading the battle-chatter. It's a common issue with Freespace mods, but it's especially rough here as Wings of Dawn is more character-driven than most. One for veteran and fast-reading players, then.
As if the mental divide you're already making wasn't bad enough, Wings Of Dawn has slightly more complex gunnery than vanilla Freespace, too. You can only fire one of your main weapon banks at a time, and the difference between anti-shield and anti-hull weaponry is more pronounced. Knock down shields with projectiles, then use energy weapons to hit the delicious ship-meat underneath, and occasionally remember to call in a supply drone to reload your ammo and swarm missiles. There's a lot to juggle, but it's worth the effort.
Wing Commander Saga (Standalone)
Wing Commander Saga hasn't changed that much since Richard Cobbett reviewed it back in 2012, and it's still one of the best things to come out of the Freespace modding scene. A sprawling 55-mission campaign, with pre-rendered FMV cutscenes and full voice acting, Wing Commander Saga makes a seriously good attempt at imitating the style of the old Origin Systems Wing Commander series, although the limitations (at the time) of the FSopen engine are obvious in places.
Where Wings Of Dawn has the option to travel around your ship and chatter with characters between missions, Wing Commander Saga makes do with enormous pages of prose. Worse still, it's in a typeface that's just a little too small to comfortably read unless you've got a huge monitor. It's not badly written stuff either -- though I would rather have a little bit of interactivity than an entire chapter of fan-fiction delivered in one big lump.
Some of the missions are uncompromisingly hard, and unlike classic Wing Commander there's no branching mission structure or opportunities to fail forward. Still, it's the next best thing to a new Origin-made Wing Commander, until Star Citizen's solo campaign launches around the heat-death of the universe.
Diaspora (Standalone) + Aerilon Is Burning
It's hard to believe that Diaspora is almost seven years old now, and still the best Battlestar Galactica game out there. Black Lab's still-expanding strategy game comes a close second and may someday overtake it, but despite using another game as a foundation, Diaspora has the look and sound of the TV show nailed down perfectly. Piloting a Viper feels every bit as twitchy and dangerous as it should, as you weave in and around the walls of gunfire filling the space between capital ships.
The only things wrong with Diaspora is that it's too dang short, and perhaps a little too easy on Easy mode, and a little too hard on Normal. Easy gives you generous auto-aim on your guns that makes chewing through Cylon ships a breeze, but Normal makes gunnery far more demanding. The short part can be partly remedied by grabbing Aerilon Is Burning - it's just one more mission, but replayable as different fighters within its single large battle. The Hard Light Productions forums contain a handful of more Diaspora missions, but sadly not as many as I want there to be.
If you're itching for even more Battlestar Galactica, there's also Beyond The Red Line on Knossos. Standalone and also voice-acted (if not quite as polished), it offers a similar take on Battlestar Galactica, although with only a couple small-scale missions. A few more missions for Beyond The Red Line are available on Knossos under the name Battlecruiser Archangel.
Special Mention - Star Fox: Event Horizon
A nod of acknowledgement instead of a full recommendation, but space combat and Nintendo fans should keep an eye on Star Fox: Event Horizon. It's a wildly ambitious fan-game, featuring a huge number of environments (many planet-side), and fast arcade combat with massive enemy swarms. Unfortunately, it's incomplete and has been on a back-burner since 2017. Developer Chasen "UndyingNephalim" Lindsey is currently working on a Legend Of Zelda strategy game, but plans to dive back into Event Horizon eventually.
If you don't mind dealing with frequent crashes and unfinished missions, you can find it here on Mod DB. It's standalone too, so just point both of the installers to your directory of choice. The rest of you can skim through the video above, showcasing some of the environments and the ridiculously large fleet battles they play host to. There's some interesting stuff in there, including submarine battles full of luminous sea-life and swirling torpedoes. It's Freespace, Jim, but not as we know it.
Event Horizon aside, all the mods and free games here are the work of large teams. Check them out on the Hard Light Productions forums for full credits, and maybe even say thanks if you liked them. This is far from a definitive list of things worth playing - if you've got any personal favourites, by all means, share. Just Freespace 2 and Blue Planet combined will last most players weeks, with the occasional sleepless night thrown in, but mods like Wings Of Dawn may be the shape of things to come, especially if its more interactive and animated dialogue system catches on.