The following questions apply to large numbers of games, so to avoid repeating myself, i'll list them all here. Users should familiarise themselves with all these points before using Project64.
Why does the game not work even though Project64 says it is Compatible?
Likely reasons: (1) Bad ROM (Read Reference > Verifying ROMS in User Manual) (2) You're not using default plugins and settings. It's unlikely that the browser information is wrong, but please check for an updated official RDB if you're not sure.
What does it mean when the game is marked Region issue (blue) or Broken (brown) in the browser?
It means you CAN play this game in Project64, BUT you need to do something quite major: if blue, Region issue, you need a different version of the game, if brown, Broken, you need a different version of Project64. Read the notes to see which versions you should use instead of what you have.
What are the best settings for the game?
Almost certainly the defaults and the ones supplied with Project64. If you have read the manual thoroughly and think you can do better, have a go, but remember what you did and be ready to put things back.
Why is the game slow?
Do you meet or exceed the recommended specification (User Manual). Is the game marked "high system requirement"? Read Troubleshooting > Performance (User Manual).
Why does the note say the game is slow, but it isn't slow!?
"slow" in this context is often shorthand for "high CPU usage" - we have observed part of the emulator using higher than "normal" amounts of CPU time in these cases. These are fairly subjective judgements. If you are lucky enough to have a fast system, you may not notice any slowdown, because overall the emulator speed stays pegged at the limiter speed. It is likely that people on slower system are noticing the slowdown that the note refers to. Just ignore the note in this case.
Why is the sound bad?
Are there any specific Known Issues noted in the browser or this GameFAQ? Have you tried enabling Sync game to audio? Read Troubleshooting > Audio (User Manual) for general points about audio troubleshooting.
Why does the game jerk/pause occasionally?
This first thing to establish that no background task on your PC is taking CPU time away from Project64. This could be something like a virus scanner, any scheduled tasks, disk activitity, just about anything. Use Task Manager to investigate and shut down as much as possible, also consider turning off services that your don't need (Win2/Xp) and programs that start with your computer (startup folder and registry).
One you have ruled out external causes, there are several things within the emulator that could cause this. The first is a plugin stalling the core, for example a video plugin flushing textures (occasionally unavoidable) or an audio plugin syncing game to audio. Eliminate these causes by changing plugins or adjusting plugin configuration respectively. The final possibility is that the core itself is pausing for one of several reasons, such as a compiler reset (rare but unavoidable) or some configuration options, Advanced Block Linking being a particularly likely culprit - try disabling ABL via Advanced tab to turn it off in all games where it's not essential (don't forget to reboot ROM to take effect). Other Settings that may help are Larger Compiler Buffer, Self-mod. Code Method, and Counter Factor. Please consult the manual for further details and do not adjust these settings unless you understand what you're doing. Some pausing may be unavoidable, depending on the game, but we have found that most IS avoidable.
Why are the graphics messed up?
Do you meet the system requirements (see User Manual)? In particular, do you have pixel shaders v1.1 or higher hardware - which are now used for many graphics effects in Project64 v1.6+? Have you changed any video plugin settings? Are there any known issues marked in the browser for this game, or in this GameFAQ?
Why does the game seem very dark?
Firstly, there are differences between monitors and TV screens that generally cause games to appear darker than they probably should. To set any level of brightness/contrast/gamma you desire, we recommend you use your video card controls (or your monitor controls!), which has the advantage of having no performance cost, and no negative effects. If your drivers don't already prodive this, 3rd party software like Powerstrip allows you to configure profiles for particular applications - you could have one set up for PJ64 to raise the gamma every time you start PJ64 and lower it whe you exit, for example. Note in v1.6+ there is a brightness slider in the video plugin options (requires pixel shaders v2+ hardware), but i do not recommend using this because there are some issues, for example brightness being applied double to framebuffer content.
Why does the game have black borders?
First, if the borders are in pairs, that is on the left AND the right and/or the top AND the bottom, especially if they are equal size, you do not have a problem and cannot and should not try to correct it. These games are designed this way, on a television you might not see it because of something called overscan (advanced users: you may be able to extend the viewable area by using the external geometry pipeline, however this often causes artifacts because you are seeing an area you are not meant to see plus there are the usual weaknesses of that pipeline). One unusual solution to this is to "simulate" overscan by adjusting the range on your monitor so the inside of the black border is sitting on your physical screen edge. You will probably want to pick a resolution that you don't normaly use so this is only used for Project64! This of course only works for fullscreen. We experimented with various methods of stretching the display to fill the area, but all caused too many problems and we decided to leave them out.
If the the border(s) are only on the right and/or bottom of the screen, or of mismatched size, then it's likely that the plugin has not detected the resolution of the game properly. Resolutions are calculated from the top left corner. The RDB should automatically handle any custom settings that are needed here for you, but if not advanced users can try adjusting emulated width and height via the video plugin ROM Settings tab. You may need to window switch (fullscreen<>windowed) to let changes take effect. 320x240 is a good starting point if you do not know the res and lowering numbers tends to shrink borders.
Why can you see through things when they're close to the screen?
There is a general weakness of the plugin with regard to the near plane, related to a limitation of the D3D API - objects drawn very close to the "camera" (screen) in the 3d world are clipped further out than they would be on the real N64. This tends to only be noticeable in some games, or at some times in other games. There is nothing you can do about this problem, however we don't know of any cases where it actually makes a game unplayable. Note this problem is much reduced now in v1.6+ with the D3D8 video plugin.
Why does the HUD or menu text look blocky?
Project64 attempts to faithfully emulate the N64 as much as possible - on the N64 games can control exactly when and what type of filtering is used, and text and HUD icons etc are often not filtered because they're designed for a TV screen, where filtering would actually make them look worse. If you wish, there is an option to force filtering in the video plugin options - on your high resolution PC monitor this can often make things look better, however it may also cause problems with the legibility of text in some games, as characters may acquire a sort of halo around them - if you see this problem stop forcing filtering (see below).
Why does there seem to be a line around sprite edges?
This is a general problem with the plugin that cannot really be solved, however enabling Force Alpha Blending may give the results you want (or may cause other problems, which is why it's under Advanced and off by default).
Why is the game difficult to control?
Remember that nearly all N64 games are designed to played with an analogue stick. Most PCs don't have an analogue stick :) We highly recommend you purchase a gamepad with such a device, or if you cannot or do not wish to, you could get better control using modifiers in N-Rage's input plugin (included, select it in Settings, consult plugin documentation for further help).