- don't be afraid to make some garbage. like any skill, level design takes time to learn, and not all of your early levels will be good.
- test your levels from the beginning, frequently. if you repeatedly die or struggle with a certain part of the level, it's definitely going to be too hard for anyone else.
- platformer levels are based around mini-challenges with breaks in between. give more breaks in early levels, and fewer in later levels (but never 0!). try not to repeat challenges – or if you do, make them a bit harder the second time, for the player to demonstrate their mastery.
- puzzle levels are built in layers like an onion, backwards from the end. start with the solution, and add one layer of depth at a time. early levels should only be a layer or two deep; later levels should add more layers, but too many layers make the solution too complex!
- place enemies with purpose; good enemy placement is designed to guide the player, not kill them. make the player want to jump onto higher ledges or use different strategies.
- add different routes through a level; a high route with more platforming, and a low route with more enemies, for example. mix it up and give certain routes bonuses or puzzles.
- use structure to ground your levels and give them a sense of place. smb1 uses horizontal structures like bricks and mushrooms, vertical structures like pipes, and diagonal structures like stairs. what other structures can you build? find inspiration from other mappacks and games.
- keep each level focused around a handful of enemies, structures, or concepts. start with simple challenges that individually teach the player; a goomba on the floor, a staircase to climb. then, later in the level, iterate and combine concepts – two goombas on the floor, a goomba on a staircase. build the player up to handling your toughest challenges by teaching them all they need to know.
Some level design tips
as most of y'all know, i've been making Mari0 levels since the day the game released, and i've picked up quite a few tips and insights over the years – so when someone on discord asked for some pointers on making levels, i hammered out a list of some of the more important things i've learned from my experience. many of y'all have seen this list already, but i wanted to repost it here so it has a more permanent home! some of these tips can be kind of broad, so if you have any questions post them in this thread and i'd be more than happy to go in depth.