Some of what people have said above is inaccurate. Please read this post.
Teemster2 wrote:The first is the note blocks and springs. Currently only Mario etc can jump off of them and not enemy NPC's but they can in Mario Maker which makes for some interesting levels. I just tested this one and in SMBX they just walk across the note blocks.
These features are coming to Beta 4 iirc with a new vertical and horizontal springboard NPCs.
Teemster2 wrote:Mario Maker has a key system in the levels where you can use keys to unlock doors to new sections. Correct me if I am wrong but in SMBX a key ends the level right? It would be nice to have this both ways.
Keys can unlock doors, barriers, and be used for keyholes. The keyhole exit will always end the level but doors, even locked doors, will not end the level unless their warp tells them to warp to another level, the world map, etc.
Teemster2 wrote:Speed runs are levels that you must complete in a small amount of time in Mario maker. Is it possible to change the times for levels in SMBX to make short timed levels? Some levels for example only give you 20 seconds to complete. Not everyone in the SMBX community would enjoy these but it could make for interesting levels.
These can current be accomplished with LunaLua (and just like an easy one or two lines of it) either via the old leveltimer.lua which is included by default on 126.96.36.199 and Beta 3, or by using clock.lua which you can download on the LunaLua subforum. Beta 4 should allow for timers to be set in the editor.
Teemster2 wrote:Tracks. There appears to be a track that you can have things follow. Think of SMW where blocks would follow a line/path. In Mario Maker they have the blue skulls follow the path but they also have NPC's such as Chomps and Flying Podoboos follow them. The tracks can go in any direction and would make for cool levels with NPC's following set paths.
Only NPCs follow lineguides, some of them just look like blocks iirc. Anyway, in SMBX2 you should either have the lineguide API or be able to download it which allows any NPC to be attached to a track, and also allows for curved tracks and other cool shapes. These will be built-in BGOs, most likely in Beta 4.
Teemster2' wrote:In the game they have Podoboos with wings and I was thinking would it be possible to make a "wing" NPC that could make any NPC fly? They also have the fire bars that they can increase the length of the firebars. Is there any easy way to do this in SMBX? They also have cannons that can shoot out any NPC. An easy way to simplify this for SMBX is to have a special cannon enemy that can easily select any NPC from a scrolldown list or something.
No idea what you mean by "firebars that increase the length of firebars". In terms of wings, it was discussed by the Devs and decided that it wasn't likely to be done. It involves rewriting and overriding all logic for 500+ NPCs in SMBX2 to do so properly. In 1.4 it's just a really janky mechanic and doesn't work well anyway.
Teemster2 wrote:This one is not really from Mario Maker but is it possible to have more than 1 item spring from a ? block when you hit it? I think it would be cool to have a block that can spring multiple enemy NPC's or even say multiple 1 ups like that special block in SMB3 did.
Just use layers and events. It's been available since before SMBX2.
Teemster2 wrote:How about water that shoots up and down? That would be cool to have and you can even have enemy's sit on top of the water to make it more interesting.
Someone did in fact make these at one point. You can currently find them in the LunaLua subforum however I've also been considering adding them as NPCs to SMBX2 when I have some time and get the current NPCs I'm working on done.
Teemster2 wrote:Mario Maker also has fireworks.I have not seen any in SMBX. These would be really cool to see. Mario Maker also has big white arrows for in the levels that could be useful to some people if they were added to SMBX. While not really anything to do with MM I would also like to see some harder bosses. It seems like Boom Boom is way to easy and the bosses we have are not difficult to beat. Is there plans to do some custom bosses to make levels more interesting and harder? That was just a thought I had. Some custom sub bosses would be cool too.
There are some new bosses like Fryguy being added to SMBX2 and the default NPCs are mostly on-par with their difficulties based on the games they came from. You can always create your own custom bosses. There are some great ones done via layers and events and more complex ones via LunaLua. Also just consider what your boss area looks like as well because you can use a default boss NPC like Boom Boom and make it much harder by just creating a challenging set-up in terms of the hazards of the boss room itself