Bone Appetit

In terms of exploration there are various progression options and decent navigation challenges but also many false walls with no clue to their existence, and you'll need to be patient early on as movement starts off slow and you might run into several difficulty spikes.

It may not be long, but the world map is very well-made, there's not much backtracking and there's a ton of shortcuts, secret areas, hidden bonuses etc. that make it ideal for multiple plays, speedrunning, or just experimenting with various stuff, since several weapons have more than one purpose.

Pretty steep difficulty curve (grinding a bit for food (which is your currency) and finding the whip helps as you can then upgrade your DEF)

I also enjoyed the goofy humor, since it's a game that just can't take itself seriously, and the original rock soundtrack made by the developer himself, which is different from the usual "game-y" tracks you hear in these pixelated games.