Wish list, limitations, decisions

Here again...

The first question in my head was what do i wanna implement into my game...

• A controlable player which can walk left and right, jump, fall
• Baddies which move on their fixed two directional way (up/down, left/right)
• Items to collect
  
• Tons of nice colorful graphics
• Animation for not only the player and enemies but for the whole screen if i want
• Music. I don't want to hear sound FX. A cool music that's I want!
  
• Lots of screens to discover
• The whole game must fit into one file. I don't want loading times.
• All moving objects (player and enemies) move by pixels not by character.
• Relatively precise collision detection
  

The primary limitation is the 64 kilobyte memory... I have to make space for sprite animations, worldmap and screen data, music, titlescreen and so on...

The decisions made so far:

• all sprites will be 16x16 pixels large. This way more sprite animations fit in memory, and i can move 1-2 more baddies on screen in the same time.
• The screen will built up from 2x2 char tiles. This way I save lots of memory, but i have to make a tileset...
• I set up tile graphics banks. Another limitation is that Plussy can display only 256 different chars (now forget IRQ, etc. :). But I want more graphics and that can't fit into a few chars (100-200 chars). So this is my idea: I divided the tile charset into banks and I can change these graphics banks in each screen. The animations also will follow this way.
• My 256 chars must have to contain these: a complete ABC, the numbers, some ! and ? signs, animated tilechars, lots of tilechars (later i call them "static"), 9 chars for the player sprite, and lots of chars for enemy sprites. I could spare some space if I cut out the A-Z letters from the charset, but I want to make a title screen also and I want to show not only text on this screen but some random ingame screen behind its text (still just an idea).
  
• I decided that the collectable items graphics will be stored in screen tile graphics area.
• Each tile has its own 4 color so I really can draw nice colorful screens :)
• I want to make ladders, walls, background (passable screen element), water (or lava, spikes, anything that hurts if you touch it)
• I didn't decide how large memory area I save for the music. If I want SID i need ~4Kb, for TED it can be less... I prefer TED music, but there's no useable TED music editors (at least I couldn't find any) which fit my requirements, only "write-your-music-with-assembler-and-compile". Too bad.