Ego's videos are entertaining and pretty insightful (especially the Megaman X one). This one made a decent point, but I don't think it was as well thought out. The whip is a little overpowered, but this is nothing compared to what has happened to Castlevania SotN and beyond in terms of how you can spam the enemies. (And I still argue that sub-weapons, since the inclusion of combos, have been greatly underutilized. Only the 64 games got it right in the balance of whip + subweapons). Anyway, the Castleroid games, as fun as they can be at times, are broken in their combat/danger (you're literally superman more often than not, taking away meaningful platforming and such), whereas SCVIV merely has some cracks in its armor. The fact is, each Classicvania was done by different people with different experimental pieces. The 8-way whip/grappling hook was an experimental add-on in #4. While it could have been explored further, as Ego's rough schematics show, it was utilized in exciting ways that no other Castlevania has matched. Just look at the Clocktower stage's use of the new whip mechanics. (It even convered the basics of some of Ego's rough ideas). Had this idea been kept, I'm sure it would have evolved and been fleshed out further--but it was obviously considered too hard to develop for most creators, which is very sad. So maybe one of #4's strengths is its weaknesses...but you know what? Heck if it wasn't one of the more ambitious CV titles. It still stands in my top 3. I doubt we'll see as innovative a title in a long time.
Plus, Uzo's note is well taken: "You neglect to mention the atmosphere, dark and detailed graphics, music, overall mood, whip swinging, great use of mode 7, excellent level design, and more." It maybe be a remake of #1, but I think it's a far more original and dynamic remake than Chronicles; it feels more like a sequel to me, honestly.
PS: Why Ego's avoidance of CVIII?!