Repost from Romhacking.net:

Kensuyjin and Marc Max have knocked it out of the park yet again. Mega Man World 3 DX is a perfect love letter to the original while improving on it in all aspects.

The colourization and animation work is wonderful. Every single stage is a visual treat, either by mimicking their NES counterparts or having their own takes on the concepts. Snake Man’s stage particularly impressed me with it’s strong pinks creating a “scorching summer sunset”-like atmosphere. I enjoyed it a lot. The reimplemantation of unused animations and adding of new effects are the cherry on top. Seeing Mega Man have the colours he has when equipping a weapon on the “Weapon Get” screen makes it help feel like the game was always in colour. I think the shine effects given to the password screen are neat, and having the Robot Master icons have their primary colours essentially wash out all the other colours in the icons when you pick a stage is extremely cool looking. Little touches like that really help bring the game to life.

What I found even more game changing, however, was the removal of slowdown and reworking of hitboxes. It cannot be understated how much this improves the game. The slowdown in MMIII was extremely obnoxious, especially in cases like most of Spark Man’s stage. It actively hindered my enjoyment of the original. Having them all gone feels like a dream. Same with the hitbox changes, I could immediately tell that things were different when I was able to get through sections that gave me a lot of trouble in the original with relative ease. The game’s much faster and more responsive, amplifying the good parts of its design while dulling the problematic ones. Honestly, the hack would be worth it even without the colour for these changes alone.

I only really have two minor nitpicks. They are so inconsequential that I debated whether to even write them here, but I thought I ought to show that I’m not simply blindly praising the hack, rather, I’m giving my honest thoughts.

Firstly, the names of enemies and the lack of spacing for the Robot Masters’ names in the credit’s roll have not been corrected. It’s not a big deal, but I feel that when making such a definitive improvement on everything else, you might as well fix innocuous stuff like this too (though Pickelman Dada is hilarious).

Secondly, the game does still feature sprite flickering. There is nowhere near as much as in the original, but it is still there. It doesn’t really cause any problems with gameplay, but it does not look great visually. I understand that it might just be a case of the limitations of the GBC’s hardware, but it’s a shame the sprite flickering could not be eliminated completely.

Overall, MMW3DX is a wonderful hack - one that I honestly would never want to play the game without. Things that brought the original game down for me, such as the level design of the latter half of the game, are much more bearable with how much the whole game is optimized, both visually and gameplay wise. It is a true showcase of the passion and love Marc Max, Kensuyjin and the Mega Man community at large have for this wonderful franchise.