You really do not unlock an item frequency changer, Johnny, I'm sorry. you also can't remap buttons, only swap what buttons do what. there's only 3 difficulties of All Star and no difficulty toggle for the CPU opponents in Smash Run outside of maybe being able to play it against your Amiibos when the 3DS Amiibo platform comes out. Things like Special, Fixed Camera, Single Button, and Coin Smash are all out.
As for Smash Run itself, I still stand by the lenghy post i made in the last Famicast episode [Episode 41] in that I really love the mode and agree that what you get out of it is proportionate to how much you put into it. Then again, I seem to be in the minority of people who really get a kick out of Smash Run.
Gui... Gui, Gui, Gui... Dracula X on the SNES is really not good. I think maybe outside of like... Haunted Castle, the Order of Shadows phone game, and Castlevania the Adventure that it's probably the most borked Classic Castlevania game, which is a real shame since Rondo of Blood gets everything from difficulty to atmosphere right [there's a reason that up until Harmony of Despair they were recycling sprites from a game that came out on the TG-16.]
There's several points of jumps you can't make without practically hanging off a ledge, cheap enemy placement, overuse of Spear Guards, medusa heads, and bone towers, Sub-weapons completley omitted, a playable character omitted, and the whole alternate stage system nearly completley gutted out besides an alternate stage 4 and 5.
Also, it has the most infamously FUBAR Dracula fight in the entire series. Sure, there are other tougher challenges like maybe Castlevania 3's Dracula or Levle cap 1 Dracula in Order of Ecclesia, but I am convinced that the Dracula X SNES fight went untested.
http://i.ytimg.com/vi/O9FX95aFyr4/hqdefault.jpg See this? that's bottomless pits you have to fight dracula around! he's also really tall so because the pillars are of varying height, sometimes you just can't hit him unless you maybe came into the fight with an axe. you might as well not even have a health bar because the knockback WILL send you into the pit. although at least the credits music is good from that SNES port and they did an admirable job trying to replicate the CD quality music from the PC Engine original.
... Also, I really like Castlevania for the Sharp X68000/Castlevania Chronicles. that game is tough as nails, but at least it's fair and I've beaten it without the use of save states.