Semi-on-the-fly remarks:

1. Controls are QWERTY-only instead of layout-independent (I have an AZERTY keyboard).
2. Wow, the (retro) music is great! :D Seeing your answer about the assets, did you create it yourself?? Mega Man vibe, somehow. This is also true for the style of the scenery. Actually, between classic Mega Man and Game Boy.
3. The sounds, transitions, animations, and details in general (camera movement…) are really great. Readability of the game seems top-notch, including putting a panel with the name of the level. (I also realize the background has a multi-layer parallax effect.)
4. The QWERTY issue makes my life hard here, as this is a fast-paced action game; my left ring finger is twisted on my (lower-left) W, while my middle finger is on my (upper-left) A…
5. The level seems large and well conceived as a platform challenge.
6. Destructible blocks! Nice.
7. The slight random direction for firing is another nice detail. I should refrain from raising all these (nice) points. X)
8. Level 2 (and already in level 1): I wonder if the weapon makes the player overwhelming… Looks like it is now a piece of cake dealing with the enemies! Maybe you should have given the player the gun at the beginning, and then lose it? :)
9. What does the game icon depict, by the way? I see three pink fish, but this is a bit small. X) (Level 5: got it, plant.)
10. Level 3 has me thinking of the Super Mario World special level (I mean, from the special star zone) where you go down amongst many yellow blocks. :)
11. Ah, the enemies call fall through our holes! I was wondering if they could, seeing their apparently static patterns in level 1.
12. Ah, level 4 becomes difficult again! :) (Once again, hellish QWERTY controls make the first vertical area harder for me.)
13. Level 5: the plants allow the platforming challenge to make a comeback! :)
    This is becoming Super Meat Boy, somehow!! :o
    Would you believe that I beat level 5 on my first try (not counting testing the very first plant)?? XD I feel sweaty!
14. Level 6: even more than in level 2, I like how you allowed multiple paths through the destructible blocks.
15. I had not noticed the character looks behind when you go backwards while firing. :)
16. Beaten level 6! Spoiler: phew, glad I understood the cover trick for the ‘stairs’ with infinite giants! X)
17. Level 7: wow, firing enemies!! The game seems to offer novelties at each level! Just a bit saddened that people may not get to see it, since there are so many games to test and it is already quite challenging to beat the 6 first levels. Tip: offer a ‘skip level’ or ‘choose level’ feature for testers.
18. Wow, how are you supposed to anticipate the big fall (going down-left) with plants everywhere?? <:o There should either be a way to guess it, or a checkpoint.
    NOOOOOOOOOOOO, you get a firing guy right after!! <:O And the (voluntary) camera lag (because of its smoothness) takes away some precious split seconds from you!! Seriously, I feel this part is close to die-and-retry. (There are various types of die-and-retry, some clever and acceptable, and some less; I read a great post in French about this, if some French-speaking people are interested here. :p Or can use an automated translator!)
19. New panel… OH NO, I had the reflex to run, but not to also shoot!! WHAT, NO CHECKPOINT?! <:O
20. Level 7 is downright EVIL. Seriously, you spiced up the difficulty way too much for a testing session!! I always try to go as far as I can in games I test, so this is devouring my time!!
21. One question: does the last bottom-left enemy look behind him (ie to his left) on purpose or is it a bug? (Yes, I have had more than my share of time to scrutinise level 7. XD)
22. Quitting at level 7 after reaching the chase phase four times and losing… I must test other games and this is hell on earth, sorry! XD

Takeaway: the game is impressive in the level of details, variety, level design, playability. I do not know how many there are, but the (almost) seven I saw are already enough. Difficulty may be too high, except if you wanted to display the full scale of what the game could achieve (in which case, well done!! XD). There also seems to be some innovation in mechanics through destructive blocks + firing enemies, and alternating running/stopped firing/disarmed enemies. My only criticism would be on the theme side (it is only incorporated narratively and remotely).

Anyway, great game. I wonder how many levels there are; I hope seven was final, seeing how hard it is! XD

Shooting mayhem!!! Well done. I didn't really cared for the story but that was because it was just so juicy to play. You have done great on the art and sound as well. Only the small screen was a bit annoying.

Amazing level design and graphics. The colors mix in very well, but I had one comment. Has this happened to me only or is it problem you couldnt fix. Cuz the game would go full screen. Idk about you but that is the only thing I have a comment on. The rest is amazing work. Great job. Liked the enemy designs and SFX too.