I've been coming around at some point to update this thread with strategy/info on the current run of MadWorld. So here goes and I'll try to dump as much as I can right now.
Firstly, I'll post two VODs of the 2:05 run of MadWorld as well as a OOB that was discovered long ago.
I started routing MadWorld back in early 2013 and discovered a bit about the game from exploits to the difficult/version difference.
Version difference - NTSC vs PAL generally will come down to NTSC since PAL might actually be slower, as the game runs at 50hz. The game is also naturally native to the Wii, so trying to play it via Wii-U doesn't affect load times or visual differences.
Exploits and Tricks - Sadly MadWorld suffers from either being underdeveloped in terms of finding glitches (IE - OOB above) or just lacks the tools to be properly broken. Despite that comment though, MadWorld does allow for some minor to huge exploits to be used, particularly the boss fights.
1. Explosive Barrels - These props in the game are the major tool for point-leeching through most levels that offer them. They offer the most point gain vs any method unless you set-up a multi-combo with preset enemies such as sign-post/tires/rose bush positioning.
2. Item usage vs specific bosses - Little Eddie, Frank, and Shamans are bosses that require item to optimize the damage vs them. For Little Eddie and Frank, you'll need to acquire the baseball bat before both fights. Bat vs Chainsaw will always come down to Bat in these fights. The gauge for the chainsaw makes the weapon limited while the bat's attack animation can be cancel once you land the initial hit in and rinse/repeat. Eddie requires subtle timing for the bat hits and the occasional dodging to avoid the power struggle. Frank on the other hand, you'll need to do the back-flip during his electric ground pound on the lower level of the boss fight to abuse invincibility frames which allows you to avoid damage and triggering his HP regeneration.
Shamans will require the torch you unlock before receiving the boss bell. Once you have it and begin the fight, you'll need to use the torch's Wii motion attack to cancel the Shaman's roll-out attack and then lock on specifically the leader to unload all your attacks on him. The trick to this fight is to avoid hitting the minions as the durability of the torch is weak in comparison to the bat. Once the torch breaks, resort to the chainsaw to finish the fight.
3. Power Struggles - I've been mixed on power struggles for a while since I played the game from casual to speedrun POV. They're beautiful as the animations will tell you, but are they practical? Answer: yes and no. It honestly comes down to which boss we talk about, the generality is to avoid them since the animations are overblown and not worth the cost of both the time and physically effort for the small amount of damage you get. Martin is a good example of this, but at the same token some bosses like Von Twirlenkiller, Kojack, and Elise require if not demand power struggles as a consent tool. In the 2:05 speedrun, you'll see where I implement use of power struggles and where I don't. This needs more looking into though before they're completed casted off as unnecessary.
4. Black Baron and Yokozuna - Both of these bosses have special skips you can perform to speed up the fights. For Yokozuna, the method is to bring his HP threshold to about 14% to trigger his stagger/power struggle animation and then proceed to simply avoid using any motion attacks. Only perform the basic four punch combo and reset his animation to stagger again and rinse/repeat till he finally retaliates. By doing this method, you can avoid all three power struggles you normally would do to knock him out of the ring for damage. (read the "Power Struggles" for more info on this) Black Baron on the other hand is different then Yokozuna. You can't abuse Baron with a combo and his skip is hard to get unless you've applied heavy damage before getting anywhere close to the final phase HP threshold. Baron will attempt to do his final power struggle against you, but during this time you can attack him and if you can bring him down to the final QTE you can save time by skipping the punch after the power struggle. (Saves about 1-1:30 min)
Difficulty and NG vs NG+ - All of my runs for this game have been done on Normal as of now and future runs might resume on Hard. Though the pressing issue is that Hard changes the point system drastically since explosive barrels are the key to progressing quickly through most of the point-grinding that is MadWorld. Unless a new route is worked out, the run might become +3 hour on Hard though this is estimating and assuming.
NG vs NG+ is a different story, as you can only do NG+ after a normal run of MadWorld. Rewards for doing so are two items that will appear on different stages and never will be together on one stage at a time. You can also skip the tutorial at the start but you'll still need to get the same amount of points you would normally to progress. The weapons are; Double Chainsaw and Katana. Katana is a faster version of the bat, while DC is just a charging weapon with no practical use.
Closing notes
That's about it right now with all the information I can muster up right now. For those who might have seen SGDQ14, you might of saw MadWorld run there. If you're interested in learning the route/run please let me know and I'll try to explain as much as I can about the game besides from what has been posted here. The end goal with this game is to get a possible sub 2:00 hour run.