based on my own and others' research
SystemID NES
0004 b h 0 RAM RNG State
0018 b u 0 RAM Game Mode
0019 b u 0 RAM Game Sub-Mode
001A w u 0 RAM Stage Timer
0028 b u 0 RAM Current Stage
0046 b u 0 RAM Current Substage
002A b u 0 RAM Simon Lives
002E w u 0 RAM Screen Offset
003E b u 0 RAM Simon Stair Mode
003F b u 0 RAM Simon Pos Y
0040 w u 0 RAM Simon Pos X
0045 b u 0 RAM Simon Life Meter
005B b u 0 RAM Simon Invulnerability
005F b u 0 RAM Simon Kneeling Mode
0064 b u 0 RAM Subweapon Shot
0070 b u 0 RAM Whip Length
0071 b u 0 RAM Simon Heart Count
0159 b u 0 RAM Simon Image
015B b u 0 RAM Subweapon
0450 b u 0 RAM Simon Facing Direction
046C b u 0 RAM Simon State
0584 b u 0 RAM Simon Substate
04DC b u 0 RAM Simon Vertical Speed
0514 b u 0 RAM Simon Vertical Direction
01A9 b u 0 RAM Boss Health
0393 b u 0 RAM Boss Pos X
035B b u 0 RAM Boss Pos Y
032D b u 0 RAM Boss Image
0059 b u 0 RAM Boss Is Active
038F b u 0 RAM Boss State
0553 b u 0 RAM Boss Timer
007E b u 0 RAM grabItemTimer
00C0 b u 0 RAM grabItemFrame
0390 b u 0 RAM Enemy 1 Pos X
0391 b u 0 RAM Enemy 2 Pos X
0392 b u 0 RAM Enemy 3 Pos X
0438 b u 0 RAM Enemy 1 State
0439 b u 0 RAM Enemy 2 State
043A b u 0 RAM Enemy 3 State
0395 b u 0 RAM Bat / Medusa Pos X
035D b u 0 RAM Bat / Medusa Pos Y
007B b u 0 RAM Item Drop Counter
057C b u 0 RAM Freeze Timer
038C b h 0 RAM Simon Screen Offset
056C b u 0 RAM Enemy 1 Holy Water Lock State
057C b u 0 RAM Holy Water Fire 1
04C9 b u 0 RAM Bat/Medusa 1 State
0393 b u 0 RAM Skeleton Pos X
0361 b u 0 RAM Skeleton Bone 1
0360 b u 0 RAM Skeleton Bone 2
0362 b u 0 RAM Skeleton Bone 3
0394 b u 0 RAM Mummy 2 Pos X
0079 b u 0 RAM Subweapon Hit Count
0464 b u 0 RAM Subweapon Shot 1 Bounced
0465 b u 0 RAM Subweapon Shot 2 Bounced
0480 b u 0 RAM Subweapon Shot 1 Direction
0481 b u 0 RAM Subweapon Shot 2 Direction
0399 b u 0 RAM Bat Bullet X
0361 b u 0 RAM Bat Bullet Y