Continuing from previous comments on Vulpine and Axolotl Stages. I replayed them on Veteran mode, and I can't say that I enjoy them, even for the challenge. The issue for me lies in layout changes and modifying multiple variables. In Vulpine:
- Floating platforms change at different rate in each difficulty. I'd rather they be one speed for all three, preferably the fastest one (Veteran). Changing them messes with players being able to route properly, because timing is key when dash-jumping off them. I would say if the platforming were simplified the stage would run just as well for the veteran type player and the beginner or casual player. The lava, spikes, and crushing walls are all threatening enough. I would say there are almost too many platforms to navigate around in the first half. Simplifying would help.
- The horizontal moving walls are a fine hazard to include, but the blocks you have to break through in order to move ahead are a pain if you can't break through them quicker or have a clean way to jump over them without breaking. It doesn't seem like you can jump over the top block in a stack of three. Either resize or raise the ceiling? The principle here is giving players options. They can either shoot through the blocks or jump over them. Maybe there is one spot they have no choice but to shoot to break through, and that's fine. Good level design offers players multiple ways to scale or run through (horizontally). A good example is Flame Mammoth Stage from X1 (after beating Chill Penguin). It's one of my favorite levels to speed through. You can skate below on the ice or chase above on conveyor belts.
- The vertical climb crushing wall sections is particularly brutal at that speed on Veteran. I'm not saying this section can't be done because of the armor that can be gained later to run it more efficiently, but this is an issue for two main reasons. First, one of the boot upgrades is not acquirable without the Flare weapon, which you get from Vulpine. (You could get the Punch upgrade from Squirrel Stage and that would work). But my second and more important point is, every stage should work like if I had no armor upgrades or special weapons. They ought to be a requirement for accessing hard-to-get areas for Sub Tanks, Hearts, and Upgrades (and other secrets), but to get through the actual stage itself, I'd like to be able to run through it as if each level were my starting stage. I mentioned in a previous comment that I like to do Vulpine Stage first because it avoids the least amount of backtracking (in Rookie and Hunter modes, I'll get to Veteran).
- The Chip Requirement in Veteran. I am fine it being all 20 to get the upgrade from each stage, but it weakens the experience of utilizing the upgrade throughout the stage you acquire them in. It would be nice to find one near the beginning of a stage, but because of the chip requirement I couldn't get it anyway unless I backtracked or re-entered the stage after completing. In Vulpine Stage, there are 18 chips before the capsule and then 2 at the very end, so you have to come back to the stage later, or run a different stage first to collect enough chips (probably the more optimal way to get it). The other downside is that you've collected that upgrade (buster charge) after most of the stage is completed. It's nice to have for the boss fight, as long as the beam damage output gets boosted a bit.
As for Axolotl Stage, I didn't even bother to run through it all on Veteran. Removing the safe spots over the spikes seems too much, and it's turning into a Fortress type stage. Again, I want to be able to run through it without the need of any armor upgrades, as if it were my first stage. I think my first memory of playing the original Mega Man X, I played through every stage and got to the bosses. My first was Sting Chameleon, and I remember getting destroyed quickly. Then I got to Storm Eagle and was excited because I killed my first boss. The rewarding part was actually defeating a boss, not making it through a tedious stage. You have some well-crafted layouts and boss fights, and the stages ought to get the players to the bosses as quickly as possible, because they are the objective. I think what's not working is keeping it more simple for anyone to run through without extra work. Treat everyone as if they are a casual player for the first time. You don't have to pay fan service with crazy difficult layout schemes. You've already built a great-looking game, a cool story based on the classic Mega Man X trilogy. The soundtrack is also really good. For the sake of raising difficulty in each mode: differences in damage, defense, amount of onscreen enemies, amount of health drops, etc. Those things I think are good for making them different. However, going back to my point in Vulpine Stage, changing layout or timing of enemies or objects within the stage is not so great, as it messes with player muscle memory and routing. Changing too many variables is more frustrating to your players, unless you state within the difficulty settings what things are changed so players know what to expect. Maybe that's something to consider.