Great effort, but unfortunately it lacks the charm of the original game!
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I applaud your efforts in remaking this classic gem. I've been patiently waiting for this for a loong time now, and the pixel graphics are nice, the 2-player mode is a HUGE welcome, the "pet" buffs twist is a nice addition for replay value, and the new level-ups were a pleasant surprise :) There are also a bunch of improvements like better-positioned platforms, more variety in the boss pattern, and easier-to-perform aerial combos!
Having said that, this "enhanced" game comes short of its original inspiration when it comes to charm, enjoyment, soundtrack, and feel. The new art style is too "cutesy" (I mean, even the skull isn't daunting anymore), the graphics and gameplay lack that "oomph" impact (not sure if it's bc of linear FBF animation or 60FPS, or both), there isn't much of a difference between the level-ups (all feel more or less the same function-wise but with varying pace and speed, except the last lvl. compare the "Fish" level in this game with the "Golden Staff" level in the original) and they lack personality, something that I personally loved about the original game (each lvl having its distinct special attack and weapon feel), and lastly, the soundtrack in this game just doesn't fit the gameplay and is lacking imho.
I feel like this game doesn't know how to position itself and is experiencing an identity crisis -- you're using "pixel art", yet the art style is round and cute, something that would've benefitted far more from non-pixel and smooth art, and so while some things look nice in pixel format (bgs, blocks, ground) other things are totally out of place like the mellow and jelly-like art and animations of the Boss (the Skull's art style reminded of Cuphead). It's like a clash of different art styles with poor results, and no disrespect to Luis' pixel art skills 😅 The "Mario"-like coin blocks don't really add anything to the gameplay and were just annoying imo -- and they just didn't fit in the game (hearing the SFX felt weird and out of place). The grinding mechanism in the original with combo-ing the gravestones was far more enjoyable imo. And the music doesn't fit in either, which kills half of the charm of this game as compared to the original one :/
Because at the end of the day, we have to compare this to the original as it's an "HD" version of it. While there have been some nice additions (pets, more details in graphics, 2-player mode, QoL improvements), the overal pace of the game and the graphical "impact" is severely lacking in this game as compared to the original game. Not to mention the pain-stakingly slow "transition" periods where the boss cannot be attacked (e.g. Tom Fulp when shooting lasers, and the Skull swirling slowly into position to shoot fireballs), and the "Level Up" transitions that last too long and interrupt the flow of the game (especially when you're in the midst of a combo and doing lots of damage, only to be interrupted by the long "Level Up" transition that lasts way too long and doesn't pause the game, so by the time you've leveled up the boss is back to an "invincible" state...). A lot of these hurdles kill the flow and make pet "buffs" useless at times.
With all these bumps and an "HD" version that lacks visual identity, the end result is something that has a lot of potential and an interesting direction, but fails to live up to its former shell. Should've called it a "reimagining" instead of an "HD" version, imho.
And I'm not sure if it's my nostalgia speaking, having grown up, or these actually being my unbiased feelings about this game, as the original is one of my all-time fav Flash games! Either way, that's how I feel right now, but maybe my opinion will change over time, who knows? ;)
A tip: placing the combos atop or close to the character would add much better visual impact than simply placing them in a corner where they're not noticed :(