If its not too late, If you want to create a simulator that does not get stale and is actually unique, then making a game that actually simulates something is probably the best way to go. Even better a true simulation game that implements some kind of preceduralism, so players can experiment and basically create their own fun.
A few ideas, when collecting trash some trash can have weird reactions to other trash that effects the game in different ways. Don’t be reserved with this either, players tend to love chaotic games, like Generic Roleplay Gaem, Neighborhood War, Runker, etc. (of course, you need other elements or the game will spike then die, like what these games did). Adding to this theme of mild chaos, you can add machines that process trash and others that turn bio-material to plant seeds or something, players will probably have a great time messing with that if their bodies can be affected by them.
Of course, when adding game mechanics make sure they’ll be fun and usable by all age groups, I feel like games like Deepwoken and Arcane Odyssey would be more popular if there wasn’t such a high cognitive floor (of course this would change how those games work entirely). While simulation games tend to not have this problem, its important to know that a good amount of little children play roblox (though honestly I think simulation games have the opposite problem, just make sure to cater to all ages).
Another thing you could implement is both more things to do (more jobs I guess) and have these things related to each other. For example, instead of just picking up trash and watering plants for the entire game play, you can give some players the option to analyze how hazardous some trash is and coordinate ways to dispose of it. If they choose not to, add in some interesting consequence to that decision. maybe some players can stake back to manage trash processors while others collect trash. Another example, You can maybe allow some player to devote their entire gameplay to eating trash, which affects them in some way (like exploding).
For the social aspect of the game, leaning heavily on the Saving the Earth idea might be good. Try to develop some internal “vibes” so to speak that makes players aggressively into saving the planet. This can be done with “Sunshine and Rainbows” music (though make sure it isn’t repetitive or obnoxious) and a very Earthy art style/game textures. This will be further enhanced if chaotic game mechanics are implemented.
Something else for players, a lot of players search desperately for advantages in the game. Whether it be some money glitch or a way to move around the map players, love it when they find some kind of advantage. With that, you could add hidden mechanics that give players some kind of advantage (or an illusion of an advantage). This could be secret teleportation spots (that spawn in corners randomly), Some trash that gives an oddly high bonus when disposed, or just randomly fill a players bucket with water.
While it probably will never top the addictiveness of Pet Systems, maybe add some wearable loot. Like a hazmat suit that eliminates the risk of trash collecting, or a steel barrel as a backpack full of water to water plants. It’ll add some grind element that is a must have for Roblox games, which honestly sucks but the other game mechanics can make up for it. I have to say it again, some grind element is the most important part of a long lasting Roblox game, Pets is the proven easiest way
Though I know that this is a lot and very ambitious, creating an “actual” simulation game requires that you consider the complexities of what you are simulating, and changing it a little to make it fun.
