Obbies, they’ve been a type of classic game on Roblox for a while now. However, when it comes to making one, I don’t really recognize the requirements for an obby to be memorable or fun.
The few requirements I know is:
And that’s about it. Pretty short imo. If anyone or an obby maker can give any sorts of tips and advice, feel free to tell me.
Make it challenging. Each level should take you at least a few tries. I notice most obbies are way too easy, even for new players.
There are many ways you can go about this; I suggest the best method is to be creative with it.
I made a very difficult obby; THE IMPOSSIBLE OBBY - Roblox and it did very well, as it was something unique, a very difficult obby which saved stages, simple but different.
Regular obbies, as in the colourful ones which are usually seen on front page are a bit over-done and saturated at this point, I don’t see much potential if you made one of those.
There are also ‘story obbies’ which is where you follow a story to get to the end, usually an NPC guiding you through the obby telling you things like “Watch out for the lava!”
There are also ‘tower obbies’ which is a concept similar to Tower of Hell.
Obstacle courses have a lot of potential if done properly, I had several ideas for great unique obbies on my group, sadly… it got locked for no reason and I got terminated, still waiting on someone to resolve that, doubtful though.
Just be creative with your obstacles, try something new, maybe mess with player controls, add crazy things to it, make the player excited to complete your game, I suggest to add savable statistics as it encourages players to come back, but of course this depends on the complexity and length of your obby, no point in adding savable stats if it’s short. Long obbies do much better as if its short, people play through once and then the game will start to die down, except if it makes it on a game-sort on the front page, then it’ll survive longer, but most cases, it’ll just die down.
A theme is a good starting point, find a theme, take it, and find out how you can incorporate various obstacles with it.
Hm… maybe try contacting Roblox Support? If that doesn’t work, guess you’ll have to make a new account and move on.
Let people test it! 
That is one of the best ways you can get feedback.
If you are hoping to earn robux from this. I would recommend making a skip stage thing for maybe 25 robux? Maybe some game passes such as gravity coils, speed coils, clouds, magic carpets, etc.
Make it challenging and make some of the jump 'unique. And don’t make it too hard unless you intend to make it like so.
Try experimenting with a cool mechanic, like gravity shift did, I really like that game. Maybe have a wall climb mechanic, so you have to climb across walls to complete some or all stages.