What would you like to find in a sequel of The Maze of Galious.
I'd like the same game play, but a complete new design of content, i.e. new layout of castle and worlds, new enemies, new bosses. Small changes to affect side-gameplay is fine (i.e. how things work with the boss passwords or continues).
And I am one of the biggest MoG fans that exist 
I'd love to see a level-editor so people can create their own levels. And SCC music, to get that Konami feeling
Coming from you and Nenefranz I'm pretty sure it will be a fantastic game!
Since Knightmare had scroll and Maze of Galious didn't, I think that a mix of the two would be something in the lines of the Dragon Slayer IV for the Famicom/NES. It would be a good fresh take on the exploration/platform on the MSX platform. Compare it to the scroll-less MSX2 version to see that the scroll really adds to the gameplay.
But please don't worry to hide the panning borders on MSX2. It doesn't degrade the gameplay at all.
Some other considerations:
1) Just a single key doesn't feel too challenging. It's almost as if the doors are there just as a decoration then. Maybe multiple key/dor colors instead? Or some doors that open only on a specific direction like KV2?
2) Some puzzle-like areas like on "The Castle", KV2 or La-Mulana would be interesting. But not tooo many puzzles, since it isn't the only focus of this type of game.
3) A more varied soundrack than MoG has would be nice. Maybe different tracks per area of the castle.
4) A good story was always something very present on MSX games, specially in after the MegaROM and Disk era.
Movable rocks are really interesting. DS-IV also have them, and it requires an item and a specific character to be able to move them.
Some (wild) thoughts/ideas/suggestions:
* SCC musix 
* mood system (Ushas inspired) (+ the accompanying pitch/key change in bgm melody )
* movable (and drop-able from edges) rocks came to mind here as well (puzzle element ala KV2 & Ushas);
So yeah, perhaps a great opportunity to implement/integrate some cool elements from other (favored) Konami games?
* perhaps some (multiple?) (sub-)plot(s), where e.g. mid-game Selene is captured and Pampas has to rescue her;
* / an advanced story line / game plot;
* in the original MoG you hardly needed Aphrodite - I guess most of us played with Popolon entirely;
* perhaps different paths/decisions to take, leading to different outcomes (and possibly different endings?);
* naming the game "Pampas" puts Selene in a disfavored position from the outset?
* RPG elements? (e.g. needing to be at a certain level to progress, some slight grinding might be necessary now & then, gear upgrades/configuration, etc.. ) (nothing too complicated though I think..);
* being able to combine Pampas's & Selene's strength(s) (to progress at points) (e.g. Castlevania: Portrait of Ruin);
* <> being able to quickly switch between characters instead of having to go through F1 menu;
* (> this could support / possibly amount to some interesting high-action gameplay: defeating some monsters with Pampas, then quickly switching to Selene dealing with some other monsters etc. )
* (> in the same train of thought this could make boss battles really interesting as well!) (need to combine and/or alternate between both to deal with it (effectively) )
* ...
@ray2day: awesome
