News: 11 March 2016 - Forum Rules
Current Moderators - DarkSol, KingMike, MathOnNapkins, Azkadellia, Danke

Author Topic: Question about difficulty level  (Read 709 times)

satb

  • Newbie
  • *
  • Posts: 2
    • View Profile
Question about difficulty level
« on: January 04, 2020, 04:18:11 pm »
Hey guys. I have no experience rom hacking so I wanted to ask for a general idea of how difficult this project might be before I attempt it. I know rom hacking takes patience and time and if this is a really difficult project I don't know if it's good for me to start here.

So I want to take the Lion King SNES rom and change the order of the levels. There is an easter egg in the game that lets you play with an upside-down sprite, but it is bugged on a few of the levels and I'd like to create a rom where you can "complete" the game upside-down.

I think this would somehow involve changing level ending code to tell the SNES to jump to a different point in the ROM? So I'm guessing some disassembly and pointers would be involved. Unfortunately, this is not a frequently hacked game and I don't think anyone has done any mapping of the ROM and I don't really know how to do any of this yet.

Anyone out there with some SNES experience who can help me decide whether to jump into it or run far away?  :P

FAST6191

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Question about difficulty level
« Reply #1 on: January 04, 2020, 11:04:10 pm »
Assembly might well be involved but there are two other things to look at
1) See if there is some kind of doorway/teleporter type arrangement at the end of a level. This tends to be more for open world maps but some platformer type things do it too.
2) While the surgical approach is favoured where you can if you want to go the other way and overwrite whole levels (presumably with the other data from the level you want there instead) then assuming it is not a case of 1) and it just cycles through them then you have your hack. If there is a nice list of pointers somewhere saying level 0 here, level 1 here... then that would also work.

As for the easter egg. You could land yourself at the end level and go from there, however most likely the game has a little flag in the RAM somewhere to say do this. Find this flag and you can trip it with a cheat.
Alternatively you can go big again and rotate and overwrite the relevant tiles to do it for you. Personally I would look for the flag if it is available as a bonus, or come the other way and see if the SNES has some kind of tile rotation and fiddle with the map but overwrite might get you where you want to go and can be done fairly easily if the game has some uncompressed graphics you can look at.
Fixing bugs as a result of the sprite that were present in the original will vary depending upon what happened.

satb

  • Newbie
  • *
  • Posts: 2
    • View Profile
Re: Question about difficulty level
« Reply #2 on: January 05, 2020, 01:25:04 am »
Thank you, FAST. These look like great things to start with. Also, I realized it may not be completely clear in my original post: I don't think I want to dive into trying to fix the levels that don't work... more like "delete" (or tell the game to skip over, rather) levels that aren't completeable. I'll start by trying to find the end of level procedures or tiles like you mentioned.

FAST6191

  • Hero Member
  • *****
  • Posts: 3054
    • View Profile
Re: Question about difficulty level
« Reply #3 on: January 05, 2020, 02:56:06 pm »
If it is a teleporter type affair then should be easy enough.

If it is a levels in order approach then check to see if the teleporter is not there for a final boss -- if there are 8 levels normally and you need to skip 2 of them for bug related issues then if level 8 comes where level 6 would normally be if done "in order" but triggers the final credits then so much the better.

After that then yeah time to play with pointers, or maybe learn to make levels and make a basic one of your own just to say it has one (even if you only walk right and see some past hits of the game or something, maybe a mini boss rush as well).