GETTING STARTED
Here are a few things you should know before beginning the game. They mostly concern pronunciation tips and commentary on some of the choices I made when tailoring this for an English speaking player. Important parts are in yellow.
What You'll Need to Play
(If you're extremely confident you know what you're doing, you can just go to the Walkthrough right now. This is just my way to safeguard players against common mishaps)
You need to have a working copy of Operator's Side for the PS2. The English version Lifeline does not have a language toggle. Make sure your microphone is connected properly, then open up Walkthrough. If you're returning to the game or doing a speedrun, check out the Speedrun Route (coming soon).
"Where are my commands?! A giant slug is attacking me!"
I will list some of the more basic combat commands directly in the walkthrough, especially towards the beginning of the game. However, since you'll be encountering the same enemies over and over again, I've gone ahead and put all combat information in a separate page known as the Quick Commands page. Please have this open in a separate tab or on your second monitor so that when the guide says "fight a red-eye slug" you can look at the quick commands, scroll to "red-eye slug" and fight it using keywords on that reference sheet.
"I just left a room by accident, now I don't know how to get back!"
Each section of the game will have labeled maps directly in the Walkthrough. Hallway maps will only be shown the first time you enter a hallway or connecting area though, so either scroll up, or have the Maps Page open in another tab. Additionally, many of the more basic rooms - like all of the guest rooms - have nearly identical areas in them (e.g. "bed" and "bathroom"). To prevent yourself from wandering places when you're not quite ready to move on, always remember to say "Tomare!" (Stop!)
"I keep telling Rio to do something and she just won't!"
Make sure the thing you're trying to do isn't something that the Operator needs to manually input (like opening shutters, inputting codes, or other special situations). If there's nothing you need to press "Square" on, try backing up a few steps in the Walkthrough to make sure you didn't miss a necessary step! If you're still stuck after everything while using the Walkthrough, please shoot me a message on Discord, Twitter, or Twitch.
If you're vaguely familiar with the way Japanese words sound, and just want to jump into the game right now, the rest of this page can be skipped. If you think you might need a little help with giving commands, read on below.
Summary: how to pronounce the letter "R", how to use simplified commands.
How to pronounce the letter "R"
Those familiar with the Japanese language may be aware that when a Japanese word is Romanized (rōmaji) - translated from a Japanese alphabet to an English one - letters such as R may not sound the way you'd instictively pronounce them. Since you'll likely be using the romanized script in the walkthrough to know how to say things like "go to the bed" or "shoot the mirror", here's a quick rule-of-thumb to remember.
Does The "R" come at the beginning of the word?
Words like "Rokkā" (locker) and "Ribingukōnā" (living corner) can be pronounced like a natural "R" sound and the game should be able to understand you fine. You'll notice that the words that begin with R are almost exclusively English loan words that begin with L, so if you're struggling with these words, try making the "R" sound more like an "L" (closer to the way the loan word naturally sounds in English).
Does the "R" come in the middle of the word?
Words like "Hidarime" (left eye) and "Tomare" (stop) may be more difficult for the game to understand if you're pronouncing it the way you'd normally pronounce the letter "R". Consider trying to add a little bit of a "D" sound on top of your "R". For example, try pronouncing "Tomare" as "Toh-ma-deh". Ideally, it should feel like you're pronouncing a letter somewhere in between "R" and "D", but the game won't demand your pronunciation be perfect!
In both cases (an "R" that begins a sentence, and an "R" that is in the middle of a sentence) the way your mouth moves will be pretty similar. You'll find that your tongue will be pressing on your gums/the roof of your mouth behind your front two teeth.
Basic Word & Sentence Structure
Particles
Most of the time, when we combine two concepts like "second from the right", and "vending machine slot" you'll see "no" の used (e.g. "second slot from the right" -> "Migi kara ni-banme no toridashi-guchi", "no" being like "of" and "kara" being like "from"). Particles are useful to keep in mind if you're struggling with doing a complex action or getting Rio to interact with an object in a specific way (like telling her to look behind something or eat something).
If you want to play around with combining commands or asking Rio pointed questions that aren't necessarily required to beat the game, I'd suggest looking up a little primer on Japanese Particles and using the appropriate one to combine words you find in game.
The game allows you to use a very simplified command structure that doesn't really require full sentences. This is why in many places, two commands will be listed one after another with a comma in between to denote a pause between words. For example, when telling Rio to run away from an enemy and then use a heal capsule, in Lifeline you're instructed to say "Flee and Recover". In Operator's Side, you can say "flee, recover" (nigete, kaifuku) without problem. So remember, if you can't get Rio to do a complex action: just break the actions down into two words that you leave a pause in between, and try switching the order of the words altogether.
Note: sometimes words will be intentionally spelled in a way that is more phonetically simple for an English audience (like removing silent "S" from the middle/end of a word). There's also kanji that gets pronounced in different ways depending on the word/context that I may have missed and will fix during proofreading.
How Good is Voice Recognition?
Generally speaking, the voice recognition in the Japanese Operator's Side should seem surprisingly friendly to you, even if you are not a native Japanese speaker nor have practiced any Japanese before. As long as it looks like the game is picking up your voice clearly (the top left vocal monitor is lighting up when speaking) giving basic commands to Rio may even feel easier than the English version. If it feels as if none of your commands work: try changing your microphone, speaking further away from the mic, speaking closer to the mic, or speaking at a different volume. Cartoonish/stereotypical accents are not required nor recommended.
The English Lifeline has gained notoriety for being particularly poor at recognizing commands. While there may be some truth to this, I think a lot of this is due to most people's experiences with the game being a first playthrough where they don't really know how the game interprets commands yet. A lot of first-time English players might waste time with full sentence structures instead of skipping directly to the word/command itself. They may use words that make sense if you were speaking to a person, but may be harder for the voice recognition software to understand because it's not trained on every possible way to say "travel to this location and then interact with that item" and so on.
Still a Learning Process
Even still, while making this guide there were definitely a few commands that I had to repeat 3-4 times. For example, I still fumble occasionally when telling Rio to shoot the "middle eye" (chūō no me), and when telling Rio to "shoot the bucket" I had to simply say "bucket, shoot" (baketsu, ute). I'm sure there are many places in the Walkthrough where I should use a more correct grammatical structure or simplify a command. I'm hoping to iron these out when I do another proofread.