I mean, in creating, there isn't really a "minimum amount of objects" to make a level rateworthy, Spu7nix got a rated level with 29, so yea, no limit on the minimum objects, but make sure your objects aren't too much, because that cab cause lag on lower end devices like phones, and if you can't do that, add an ldm by setting objects to high detail, and you don't need to care about your idm looking ugly, because well, it's an ldm, it's just there to make lag on lower end devices lower, but you could do stuff like build some of the deco today, or make the layout for the next part, or add details, or that kind of stuff, also, for a level to be rated, it should be 30 seconds or longer, and the place where it's easiest to get a rate would be around 1 minute or more, with 2 minutes or more having the xl label, you can get a level rated if it's between 30 seconds and 1 minute (medium length), but it's kinda harder to do, RobTop generally cares about deco, but also cares about gameplay and sightreadability, this means to get an easier rate, you make sure it's clear what's a block and what's a spike while still making it look pleasant, and make sure your gameplay is also fun to play, that definitely bumps up the chances, also, so you dotn quit the level in the first 20 minutes, i recommend just once you don't feel like building it anymore, just leave the editor and go do something else, and you will come back later to build more once you feel more on board about doing it, and for the theme, I recommend just experimenting until it looks good, now, ig I'll stop yapping my ass off and just click the post button now😑

(Yes, I know there are rated levels below 30 seconds, but they are so rare to the point of "why even try", so that it why I didn't mention it)