What happens when you improperly copy a game from the Arcades, and put it on a system that is capable of having an almost perfect arcade port? You get Bikkuriman World, which is a worsened version of Wonder boy II gameplay wise, and I'll tell you why:

The graphics here (for regular enemies) are just copied from the original arcade version, nothing to see here. However the main problem comes from the new bosses. They're just the same, but reskinned. No big difference! But this affects gameplay, and I'll tell you why soon.

Sound here for a PC engine game is...great! I mean, yeah the sounds played are at a lower pitch, but if you ignore that the sound is perfect! Just like the arcade game.

Now gameplay...that moment when character designs make the game harder. You see, some bosses have been redesigned to fit in with the Bikkuriman theme, but whoever programmed this game should've designed it to fit in with the original arcade hitboxes. And you wanna know when this is most prominent? The boss on level 3 has been made harder due to the fact that its movement has been changed (from memory) and some minor changes to its behavior. This makes strategies you made by playing the arcade game obsolete, so you need to get in line with this new boss. And also, did I tell you this boss can put you into a corner & attack you forever without escape? Yes, that has happened to me, and I blame it because of how HUGE this boss is. I mean, 3...main characters tall? That's large! It'll take up most of the screen! Yet how did the developers let this happen? Back to graphics, some of the new designs made bosses harder, right? In the level 2 boss, the Superdevil's fireballs can ignore your shield? In the arcade version, yeah your shield had the limitation of having no vertical protection, but even when the fireball CLEARLY hits your shield, it ignores it all together.

Now going back to the review, depth here is an 8, 1 point added for actually having a competently made title screen. The original arcade's version was just pictures in letters, but this one is stylish, even featuring a zoom in of the main character!

Difficulty has been increased because of my previous experiences with this game, and the fact that the developers made the game harder with minor register bugs & odd design choices.