Part of my level series, Mega Man World! (Yes, it shares a name with something official. Not specifying it this time though, I've done it eight times.)
Here, you're venturing into Wily's Castle. The castle entrance is guarded by many enemies, including Pukapellies, Tom Daddies, and Bitters! And a certain annoying yellow blob's back... No offense to it.

If you'd like to get the experience of playing a full game, play the previous robot master levels first, then this, then the future Wily stages!

Bonus Comment:
I uploaded this the exact same day I started building it, which I haven't done in a while. Now that I don't have to stick to too many specific themes, I might roll these out much more frequently! ... Also, one more thing. Who else sees the creepy clown face on the Wily Castle? It looks like it's chewing a bouncy ball! Well, anyways, see you at Wily 2. (That rhymed!)