Unfun hack. Player-unfriendly and annoying design choices all around. The most notable problems are the awkward low-ceiling jumps, the tremendous overuse of item babysitting (in almost every single level!), the completely arbitrary lack of midway points, and the inherently bad custom sprites. Especially the latter; spammy suicidal hammer bros, unfair rocket barrels, and earthquake thwomps come to mind. Not to mention the bosses, which are all just sadistic pieces of shit. Homing bullet spam, stunning you for way too long to recover, pickupable blocks with too much velocity, you name it. Couple that with long castle stages and the whole no-midpoint thing and you've got a perfectly legit reason to ragequit.
I came across a few bugs as well. For starters, the teleport block in Dark Waters stopped working at one point, and I had to kill myself. Later on, this happened again in Shell Castle, where I had to wait for the timer to run out. Also, some levels use the glitchy upside-down dirt tile.
Visuals and whatnot are fairly boring and predictable. They're not bad per se, but the creator clearly didn't make an effort to stand out. Uninspired concepts, overused music, underwhelming graphics.