I tried searching for a thread like this, but I can't seem to find one, so I guess I'll make it. Try to list as many retail games as you can think of that have a debug menu in them, as well as any discerning info that would be important for other members to use for google searches. I'm sure much of this will be old news to most members. However, we aren't all gods here, so I'm sure there is something which someone believes is old news which is actually new to someone else. The first game I know of is Bloody Roar 3 for PS2 (SLPM-62055) with the options menu highlighted, press L2 + O on controller 2 to load the debug menu. The cropping in the picture is due to me messing with the games aspect ratio. The next is Final Fantasy X-2 for PS2 (SLES-51815) You can activate this with the use of an Action Replay code. However, once you're in the debug menu, you can save. If you load the save in the debug room, (you guessed it) then you're in the debug room. Using a save is the least-effort way of accessing the room. This next one probably doesn't count, seeing how it is fan-made, but it is still impressive nonetheless. It is Grand Theft Auto: San Andreas (PTMG mod) for PS2. I'm believe that this game is in Portuguese, but the in-game dialogue and menus are all in english (for us lucky english speakers). You activate the mod by pressing R2 + UP on the analog stick, and you get numerous options. Get any weapon, spawn any vehicle, be 100% fat, be 100% muscular, etc. The next two are extremely old news. So old in fact, that its really not worth going into them in any detail. Both the Resident Evil 4 and Biohazard 4 trials have debug menus within them. The next game is Devil May Cry 4 for the PC. I'm still working on getting this one to work, but there are numerous videos on youtube that show that this isn't a rumor or fake. It has something to do with the executables in the Polish release of the game, which has the debug menu left in. It seems only accessible when you press all 4 trigger buttons on a (360?) controller connected to your PC. http://www.youtube.com/watch?v=D2jJJx36eug&t=1m52s in the comments of that video are links to the forum where they are working on porting the debug to the Multi-9 and Multi-6 versions of the game. And the final one that I can think of is Super Smash Brothers Melee. All 3 revisions of the game (1.00, 1.01, 1.02) all have this left in, and are accessible with Action Replay codes. There are lots of options to configure who you are playing as (giga bowser, sandbag, etc), as well as an option for 6 player melee (4 humans, 2 bots). Ok. your turn.
Dragon Force, Battle Arena Toshinden URA, D-Xhird and NiGHTS for the Saturn are known to have debug modes, though I believe the latter's can only be accessed through use of an Action Replay code.
D-Xhird's debug code is accessed via a pad input during the Takara logo. I had no idea that Tohshinden URA and NiGHTS had debug codes though.
Most Square games on the PS1 have a debug room that can be accessed with an Action Replay. Off the top of my head FFVII, FFVIII, Tactics, Xenogear, Vagrant Story, Parasite Eve and a few others have them. Some of their SNES games also have them as well.
Sonic Pocket Adventure on the NGPC has one but it's not accessible on the real hardware (can't remember exactly why). Most Sonic games seem to have cheat-accessible debug mode, I know Sonic 2 does and I seem to remember Sonic 3D having an accessible debug screen if you knock the cart. For some reason I can only think of Sonic debug right now, I'm sure I've messed around with others.
There's one in Goldeneye 007 on the N64, accessible via a Gameshark/Action replay. NTSC only I think.
The debug mode in Toshinden URA is something I only recently learned about, and ironically it's quite similar to the features in D-Xhird (which makes sense when you consider both were "ghost" developed for the Saturn by outsourcing company, Nextech). As for NiGHTS, it was believed for years any debug menus could only be accessed in pre-release review copies of the game. However, it was recently enabled in the retail version through use of the Action Replay cartridge - here's a link for all the information you need: http://www.nightsintodreams.com/?p=421 I could forgive myself for not remembering that Silhouette Mirage has a debug mode... but the Sonic games? I should hang my head in shame after forgetting the classic Megadrive games with their rather brilliant editor modes... and to think I once bought DC:UK magazine just for the cover disc that allowed you to play with Sonic Adventure's (rather limited) debugging options as well! Andretti Racing on the Saturn also has a rather fantastic hidden menu that allows you to adjust your fuel amount, number of laps, enemy AI and even the centrifugal force to make slipstreaming easier or trigger incredible crashes where your car flips as if there is no gravity!
Thanks for the link! Nascar '96 on the Saturn has a debug menu that lets you alter many aspects of the game plus run the game in Wireframe mode. Wipeout 2023 (Wipeout 2) on the Saturn also had a debug mode which again lets you play in Wireframe mode as well as many other cool alterations.
I'm not sure of the exact issue number, but there was a demo version of the Action Replay CDX disc given away with DC:UK once that contained - in addition to other things, such as full items for the trunk in The House Of The Dead 2 or being able to turn off the clock in Crazy Taxi - a code to enable Sonic Adventure's debug mode. However, it's not much to write home about as all it does is highlight whatever polygon your character is in contact with, plus it makes all collision boxes visible (including a "shield" surrounding the player model) and displays some geometry/position counters. I'm hardly surprised NASCAR '98 has similar features to Andretti Racing (including the wireframe mode, which I forgot to mention earlier) as it's the sequel in all-but name and even uses the same basic engine. Also, I knew about the wireframe mode in WipEout 2097... but does it really have other debug features? I'd especially love to know more about those!
I wouldn't call the wireframes modes in Nascar '98 and Wipeout 2097 debug modes, just added features 'for the sake of it'.
The original Earthworm Jim on Genesis (probably on SNES too) had something that looked like a debug menu. I guess it depends on how you define a debug menu, though.
i would consider something as small as room jump to be a debug menu. anything that allows you to break the rules of the game without the use of a cheat device (even if a cheat device activates it)
NightWarriors for Saturn, Mortal Kombat Trilogy for anything... more than 50% of the games, I believe?