First things first: Read the reddit, this is the source for most of this information
TLDR: If you want the game to be "fun", start in Counter+Speed mode, and clear boards as quickly as possible until you hit 50%; then switch to Knockout and just try to eat ghosts and stay alive. When it hits 10% consider camping power pellets.
There are three sources of danger in this game.
Ghosts: These behave like the ghosts in normal pac man. Touching them will kill you. Power pills make them destroyable.
Gray Pacs: These will slow you down. The act of eating a power pill will destroy them. They are mostly harmless but if many swarm you at once they can freeze you in place long enough a ghost kills you. (The reddit calls these "jammers".)
Red Pacs: These chase you like ghosts. Touching them will kill you. Power pills will freeze them, but they are still deadly while frozen. The act of eating a fruit will destroy them.
Eating a blue ghost will send garbage (gray and red pacs) to other players, determined by your target (select with right analog). Eating a "small ghost" will add to a train of blue ghosts on some designated ghost. The game tracks if you eat many blue ghosts during a power pill session (ie, without letting the power pill state drop), but there is no bonus to eating all 4 ghosts.
If you have eaten like 60% or something of the pellets, a fruit will spawn. Eating fruit will reset the board.
Speed boost: This is the most important, and least obvious, thing about this game. If you eat every pellet on the board (including power pellets), you will permanently gain speed. Your count of speedups is tracked on the board as "speed:" (starting with 0).
Power ups: The "right hand side"/right-stick controls control where you target garbage to, but the "left hand side"/right hand face buttons give you a "power up". The power up activates when you hit a power pellet; just hitting the face buttons has no effect by itself. The interesting power ups are standard and speed. Speed will reduce your garbage power slightly (75%) but also speed you up. The other powerups come with penalties.
"Stronger" penalty: It's really important to be aware of the problems with "stronger". Stronger will double your garbage, but it will also (1) greatly reduce power pill time and (2) permanently give you a large speed deboost, one time, the first time you eat a power pill with "stronger".
Lines: At any one time there will be a number of lines stretching from the board of enemy players to the bottom of your screen. This is the number of people attacking you. This leads to a nonobvious consequence: If there are many lines stretching to you, the power of "counter" is implicitly increased. In all "Tetris 99" series games, "counter" is capable of "duplicating" garbage by sending the same amount of garbage the other methods would send, to an increased number of targets.
Grinding: If as you are about to make a turn, you hold the direction you're about to move, sparks will appear. In Pac Man CE and CE DX these sparks mean you get a slight speed boost. You should be grinding at all times.
Ghost AI: In the original Pac Man, each of the four ghosts had a "deterministic" AI whose behavior is completely predictable. If you read old Pac Man guides you can learn exactly how these ghosts behave-- assuming 99 uses original Pac Man AI, which I haven't proven (Ms Pac Man AI is less predictable, for example). Unless you want to get REALLY into it though the only important thing to know is: Sometimes the ghosts will make suboptimal decisions. (The red pac man AI seems better).
KO "credit": All Tetris 99 engine games appear to give credit for a KO to the last person to send a player garbage before they die. You can game this by, in the first phase, sending lots of garbage (therefore counter-- most deaths in phase 1 are random) and in the second phase using "knockout". KOs mean you get badges; if the meter at the bottom and the other Tetris 99 games are a guide, badges will increase your garbage strength but also make you a target ("hunter" mode).
Meter extension: Every time you eat a blue ghost, the "power pellet time remaining" meter in the center of the screen will gain a little bit of time. The extension is very short, but it's long enough to have one important effect: You can never run out of time in the middle of eating a train.
This game is really all about the red pac men. Nothing else is a credible threat. Your goal is to survive the red pac men. If there are no red pac men on the board yet, your goal should be to build up speed levels, so you can survive the red pac men.
You can think of the game as being played in three phases.
Phase 1: Just before the game starts, hit "A" to switch to Speed mode and left-on-rstick to switch to Counter mode.
Your goal in this phase is to clear as many boards as quickly as possible. You want to build your speed level up. Nothing else matters.
If you get a chance to eat a ghost, great. If you get a chance to build up a train before eating the ghosts, great. (If you notice you have very few "lines", like only one, you can hit up-on-rstick to switch to "random" mode temporarily because at that moment you are not getting much benefit from counter.) But in this phase ghosts/garbage are bonuses and they are not worth sacrificing significant time for. It's good to gum up other players but it is unlikely anything you do will kill them in this phase. Resist the urge to eat the fruit. If you eat the fruit early you have wasted time and time is a powerful currency in this stage (because it gives you a chance to get speed ups).
Occasionally you will get a board with no pellets, only power pellets. In this phase, if this happens, get the fruit immediately. You will not get a Speed Up from this stage and again, in this phase only speed ups matter.
Phase 2: When the number of remaining players hits 50, red pacs start spawning. Hit down-on-rstick to switch to Knockout mode-- garbage is more likely to be deadly at this point.
In this phase your goals shift. The goal is to send garbage so other players hit red pac men, and survive. You can continue to clear boards until you get your first red pac. But once you get a red pac, everything changes.
Once Red Pacs appear, your goal is to stay in blue ghost mode as long as possible and eat enough pellets to spawn a fruit. Once you've prolonged your blue-ghost period as long as you can, eat the fruit and clear your red pacs. The goal is to keep red pacs frozen until you can kill them.
Remember, red pacs mean you can no longer clear boards. Since power pellets freeze but do not kill red pacs, the red pacs will almost certainly block you from getting at least some of the normal pellets.
It is worth it to delay getting both power pellets and fruit as long as feasible. If you collect the power pellet too early, it may be missing when you need it. If you collect the fruit later, there is a chance a red pac will spawn while you are delaying collecting it.
If you find things are moving too quickly in this phase, you can hit Y to switch to Standard, slowing you down but giving you a garbage boost. Warning though you may miss that speed if a gray pac hits you, so be ready to hit A again if you need it.
Phase 3: When the number of remaining players hits 10, garbage will start appearing very quickly. This is important because in this phase, gray pacs become a serious threat. Gray pac swarms happen frequently and they are large. You can get stunlocked for seconds in a single place, and then a ghost will get you. In this phase it is critical to eat the power pellets strategically because it is the eating, not the blue-ghost state, that destroys grays. Delaying eating the power pellet and staying near the power pellets can help with this.
In this phase, camping the power pellet may be a good idea. Hanging out in a corner right by the power pellet and waiting for either a threat to come near or a large bunch of garbage to dump means that you will destroy as many graypacs as possible, and ahve the clearest path to the next power pellet, when you do eat it.
When the number of players hits 3 or 4, it might be advantageous to switch to "stronger" (and suffer the speed hit) to take the other players out quickly. If you reach this point you are a better player than me. Good luck!
- Practice that "A button, rstick right" maneuver to enter when the game starts. You might not have much time to enter it if you've zoned out in lobby mode! (And remember, your starting power up does not apply until you eat a power pellet.)
- When you hit the top three, things do speed up-- be ready for it or you may be surprised by how quickly the red ghost can move and how much harder controlling becomes.
- Red ghosts can spawn right in front of you. This is annoying. If you're in phase 2 or 3 be ready to flinch backward at any time.
- Power pellets do not count toward the board clear/speed up credit. Ever. If you eat the last pellet and you DON'T see the "speed up" message, you probably just missed one.
- Eating Gray Pacs on purpose can occasionally be worth it. Don't eat them just because they're there-- remember, they clear out anyway when you eat a power pellet-- but if you're already in blue mode, clearing all the Gray Pacs so you can take a quadrant at a more leisurely pace before taking the power pellet can be a good idea.
- Remember, eating fruit does NOT clear gray pacs, so gray pacs can be very dangerous when you go for the fruit! Being in blue-ghost mode will help with this.
- If the background animation is distracting you, you can turn this off by going to settings and using the unclearly labeled "X ENABLE ANIMATION" button. It is still hard to read the labels tho.
- A weird, almost hidden mechanic: Once per match, vertical arrows will flash on certain points on the board. Until that moment, ghosts cannot move through the spaces where the arrows appear; after the arrows flash, they can. Is this useful to know? No idea.
- This document talks only about Pac Man 99 strategy and not basic Pac Man strategy. This may seem obvious, but the most important thing when evading normal ghosts is to not get trapped from two ends at once. They don't chase you very well so if there's only one in a quadrant it's easy to avoid, but if two get in a quadrant they're likely to trap you in a corner because the slightly differing AIs make it likely they'll go opposite ways. When you get a power pellet all ghosts start running away from you at once. Ghosts get locked in the closet for a short period after you eat them, so even aside from generating garbage it can be advantageous to eat ghosts at regular interval to keep fewer hazards on the stage.
- Is the background so noisy it makes it hard for you to focus on the game board? Go into the "Settings"->"Custom Theme" screen and press "X" to turn background animation off.
- What exactly is the ghost AI? Pac Man 1 rules? Ms Pac Man rules?
- Is my description of garbage duplication in counter mode above correct? I'm certain Mario 35 worked this way, but this version less so.
Contact me as @mcclure111 on Twitter, or below, if you have comments.