Idealy they should be invested in the game until they feel satisfied with what they achieved, you don’t want to make a game you only get invested for 2 minutes and feel like you need a refund for your 2 minutes, you want to make a game that, let me talk like a brand here, inspires them to make better things, make them have fun with their family and, most importantly, fund their childhood and give them nostalgia when they play it again, and even when they’re old they still enjoy playing it.
You want them to invest around 30000 hours of playing, that by itself sounds ridiculous but you’re not here to make a game called “idle slayer” (that was literally the first thing I found in my play store, and it was really generic), you want to pull a minecraft, a gta V, a Garry’s mod, a team Fortress 2, a game people genuinely enjoy and that they end up investing 20 thousand hours on it because the game mechanics are NOT ADDICTING, but really engaging. I can’t say minecraft because minecraft doesn’t record play time, but I know a speedrunner (DarkViperAU) who has 7000 hours playing story mode, and in TF2 I know someone (MrSwipez) who has around 10000 hours. If you Manage to pull that many hours in your game you did it right. The question is how.
I will tell you what anyone would say in a roblox game: put daily rewards, goals, put level ups, make constant updates, give them daily loot boxes and put Twitter codes in your game.
That. Is. The most generic type of roblox game I can imagine, and i genuinely believe that if you go for those strings you’re destined for an average game.
I can’t tell you exactly what makes a game huge because I myself am not someone who made it big on roblox, but here’s what I would say:
Have engaging mechanisms, how do you achieve engaging mechanisms is more complex than you can imagine (as simple as it can be, think that game types such as exploration and shooters are based on primal instincts, our ancestors would go around the planet exploring for new places back when they were nomads, and shooters give the primal instinct that is like a sin, of having a position above someone else and having an impact in what you do (you want your gun to be LOOOOUD, not “pi”)),
give the game an ability for the community to keep it alive, even when you yourself can’t (minecraft has a huge community drive, mods, maps, servers, online contact and a diversity of playstyles. Gta V has a huge community drive, mods being the most impactful. Tf2 has a huge community drive, people make their own servers, balance the weapons the way they want it to in their own servers, gives the ability for players to make their own maps, weapons and hats and they can get in the game at some point even, it even has its own ####### economy and it hasn’t been updated since 2017. Garry’s mod lives of that community drive, but I don’t know it clear to talk about it.)
Give it a skill to master, don’t make the skill floor be on the ground and the skill mastery on the ground too, you want players to improve the more time they spend with it, even if it is 3000 hours (you can go to minecraft and try to build the best thing you can imagine and it will most definetly be a wood hut with a grass floor, but some skilled players managed to build an entire ####### city on the game and that took a lot of skill. You can go to tf2 and manage to get a score of 1 or 2 the first time, but the guys who have been for 3000 hours will get 223 points. You can go to gta V and start a new game and you’ll be level 1, some people are even level 1000 legally. Garry’s mod? Yeah, it’s there.) (YOU DO NOT WANT to make the skill of the game just holding click, you want them to be active with their movements and have a reason for their movements, and those movements don’t express ahsjdjebcwjjxnejdkddn, but a skill they have)
Making games isn’t easy, there’s a lot of technical that I can relate to because I am engaged in game development in things away from roblox, and when I come here and see the games that people play I can’t help but think: damn, what a wasted potential. Not talking about every game, though, I got engaged with lumber tycoon 2 because it accomplished a lot of the things I mentioned here. There’s also the creative aspect, some people (ME) want to have the ability to make a creative thing they imagine, and it’s almost always a yes for games, whether it’s creativity on building a farm or creativity on the way you play the game, it’s useful in a lot of cases.
A roblox game doesn’t always achieve 10000 hours of gameplay, but it’s possible that you can do it, and even get an (adult) audience engaged in your game because it’s not a rainbow obby but a game everybody can enjoy, like the series everybody enjoys (oldest SpongeBob or oldest the simpsons)
Edit: one thing I forgot to mention that I find fundamental is that, in whatever art form you’re doing (games being one) you want to achieve replayability. Viva la vida has replayability, Interstellar has replayability, the halo franchise (from 1 to 3) has huge replayability, and it helps that their devs know a lot of game designing, they even backtrack and start over if the game is not fun, they don’t get satisfied with mediocrity. That was ex-Bungie, now 343 industries doesn’t know what they’re doing and hasn’t been able to be the sole holder of the Xbox, maybe your game in roblox could be the next one, hehe…