This is amazing! What can I say? This is a game done right in its genre!

Pros:
-solid gameplay, responsive controls overall
-good level designs (enemy placement, hazards, platforming)
-Great boss and sub-boss battle
-stage and enemy variety
-easy to understand weapon upgrade system
-Nice music and audio

Cons: *minor things and I'm sure will improved with time as this is just a demo*
-quite difficult for a first level, maybe that's just a demo and will change? Damn you treadmills+battles!
-can't grab stair by holding up on control, has to press up when in front of stair. (frustrating)
-pause menu(change weapon, recharge energy etc) does NOT pause the game and you die in mid battle. Is that intentional?

Good demo. Although I felt the jumps were a bit off, especially near edges, and the difficulty of the first stage was surprisingly a lot harder than the second - it's a great proof-of-concept of what could be a decent action-platformer in the vein of Mega Man. Apparently I just quoted the description, but I swear I wrote it before I read the description again.

There was also an issue with telegraphing in the first boss, it wasn't very easy to tell there were other platforms at first glance, and ducking could be a bit faster, as well as the shield skill but those are minor gripes. The semi-randomized levels were a nice touch too (i.e levels were hand made but the usage and order of the levels change a bit.)

Looking forward to the final relase.

For a demo, this is really exciting. I can't wait for the full game.
I did notice.
-when using a controller if you push buttons while its loading the character in the level the game will freeze.

Rokko Chan X!! The game looks quite promising. I hope the final product will be well polished and at an affordable price. I don't think of it as the Megaman X we couldn't have because we had 6 of them (not counting 7 and 8 since they are quite different), I think of it as a competent clone and I hope you change your description. I like the idea of upgrading and will be quite challenging not to have a dash button, but you should also drop the "right weapon" mechanics for the bosses and focus on attack patterns instead. The shield should also have a limited use in high difficulty.

My complains are that it seems it needs a hi-spec PC to get full speed with the Render Quality option set at high, something I find kinda pointless considering the graphic style is retro-pixel. Which takes me to my other complain: the graphic style. "Retro-style" is been done to death, maybe you should add the option of hand-drawn hi-res graphics, that would be something new, no more 8-bit, 16-bit, 32-bit style crap. If the game is good, even though the game is like the games from the late 80s and 90s, you don't need to yell "retro" in every pixel.

I hope you change your story too, it's way to similar to Megaman X! Maybe you can make them cyborgs from a rival republic or a robot conversion gone wrong or an invasion of mechanical beings from outer space or another dimension, but please, please, not robot servers gone bad and turned against their masters, it's so cliche'd and we have the Terminator and Megaman series and certain mor-n who claims to be mighty for that already.

The music sounds good and not so chiptune, I hope it would get even better. Since the game looks more Amiga-like than SNES-like, maybe some protracker-like music will add more to that Amiga-mood I got. I'm looking forward to see the final product. Good luck!

EDIT: After playing more of it, I have some suggestions to make:
Although I didn't find the difficulty too hard, some younger players will find it quite hard for the first level, maybe a first-time only lower difficulty for the earlier levels will prevent you from getting bad reviews for the high difficulty, I don't understand it but a lot of good games have gotten bad review for being hard.
A diagonal shoot would be very welcomed too, it will change some mechanics and would probably require a different enemy placement but will also help the future complains for high difficulty (I can't believe it's an issue these days, it used to be a big sales factor).
There should also be an upgrade for the hands so that the character could stick in place to the walls rather than slowly slide, that would help to distant the game from its inspiration material.
And finally, there is a typo in the shop, it says "Stage Sreen".

There is also a side issue that I don't think it's your fault but maybe you can fix it anyway: for some reason, AVG is detecting the demo executable as a potential threat and deletes it.