My suggestions would improve the game vastly, especially to those that play fighting games and such. The Dev with the Hadouken in its current version is just paying homage to X1's Hadouken, which is fine if he just wants to include the easter egg as it was in the original game, but I'm just saying that it could be better, since as a fan game that does not have to follow things exactly as they were before in the official games, the Dev can take liberties especially so that their game can stand out more.
For X to deserve the headband that he was given when acquiring the Hadouken in this game, he shouldn't feel as clunky as it was in X1 and X2 with the Hadouken and Shouryuuken in those games, and the suggestion I made would still let people enjoy the benefits of the 1 hit instant kill attack, while also giving options for the people that enjoy fighting games, so it would ultimately be a win win for both types of players, since even the Mega Man Zero games would let you use Zero's charged moves, without having to hold down the buttons for said moves, by executing the Shouyuuken inputs once you obtained the ultimate forms for those games, which not only made the combat more combo friendly, but it was a nice reward for essentially obtaining the collectibles and stuff. Even the PS1 X games would let you combo off some moves, so I'm just saying that the capacity for combos has always been in the DNA of those games. If you have no idea what the Shakunetsu Hadouken is, in many of the Street Fighter games it was just a special input for the Hadouken, and games like Super Smash Bros 4 and Ultimate when they added Ryu to those games, they made the special input available by doing a quarter circle forward, which would make the Hadouken obtain fire like properties and made it stronger, and I think that input would work for this game if the developer did decide to take my suggestion into account.
The stage suggestion is also very important, as this is supposed to be an alternate timeline where Sigma had won, but as you play as X and beat the bosses, there just doesn't seem to be any sort of showing that X is actually making a difference, and when Zero was put in a similar situation to X such as in Mega Man Zero 1, where Zero was fighting against Neo Arcadia which was the government in power during that era, from the moment you started that game you saw how the Resistance was barely scraping by with their placeholder base essentially, and as Zero did missions for that game, you would be shown how the Resistance improved their living conditions, and that made the experience more fulfilling as it felt like your time as Zero was truly making a difference in that place, but in Regenesis since the stages don't change at all, it literally feels as if what X is doing is pretty pointless, since no actual differences can be seen, and the least that the Dev could do would be to reduce the amount of enemies in stages that no longer have a boss, although I would prefer if there was a domino effect like in X1 or X3, that affected other stages.
This game has a ton of potential that I would love to see realized. Even if the dev themselves does not have much experience with game development, if they just ask members of the community, I am sure that this game could head into the direction that it deserves to go, because just look at projects like the X8 Demake or even the Mega Man X Engine, where through the hard work of the community those projects keep becoming greater, and heck even official games like the X Dive Offline version, actively keeps receiving new mods and content even after Capcom released an unfinished version with tons of content missing and had the audacity to charge $35 for it, but the community not only restored a lot of the missing content, but they are actively making new content, and I can only hope that someday they manage to reintroduce online modes like the PVP that was featured in that game, since I think that was the best system in that game when it had active official servers, and since projects like Mega Man Arena exist, there are already people with experience with similar projects, so all that is necessary is to make the folks working on X Dive Offline, somehow figure out a way to work with the folks at Mega Man Arena, since that game even has Co op stages to play with friends like the original X Dive had. In the hand of the fans, Mega Man will never truly die, unless Capcom one day pulls a Nintendo and starts claiming copyright everywhere, which could someday happen as things like that tend to happen when leadership roles change within a company.