Honestly, sandboxes live and die on the quality of their implementation. Unlike a completely linear experience, or a vastly simplified "3-6 buttons for naviagation, super limited options", that only really requires the ability to frame a scene, write dialog, and pose / render models ... a sandbox requires real, honest to god, game desing.
And honestly, who here is a real game designer with 5-10 years of experience? Maybe one or two people who decided to try an inde / passion project route. But the vast majority, I think it's safe to say, are not.
To make a really good sandbox, there has to be reasons for it to be a sandbox. Liberty, freedom, multiple possibilities. Exploration and discovery, maybe repeatable events, maybe character placement in the world is super important. Schedules, events, etc.
Then on the other hand, you ABSOLUTELY - MUST - NOT - WASTE - THE - PLAYER'S - TIME. If your game is designed in such a way that you need to click on your bed to sleep on the end of the day, each and every time. And to get to your bed you have to:
- Leave whatever building you are in. Maybe this means leaving several rooms
- Go to the overworld map
- Click on "Home"
- Navigate from the front yard, to the house, to the living room, to upstairs, to your bedroom
And you have to do this every time. Oh and sometime mazes, cuz you click on arrows and people might forget where the room is. This is tedium. For me, it induces downright disgust with the game. Such a poor design, and so incredibly common. A quick solution is a "Go to sleep" button, or "go to your room, no matter where you are". And other things.
But again, the maze navigation is horrible.
Next would be the topic of searching for characters and events. How do you progress the story? What stupid fucking thing do I have to click on to make things go forward. I've jsut played such an experience today. In a certain game, I had to have a random event happen in the day. Next morning I had to make the character masturbate, but not go all the way, then go to the shower to trigger this evnet. How did I know that all these moon-logic steps were required? A fucking walk-thgrough, cuz that was pure fucking insanity, worse than the worse moon-logic puzzle games I've ever played.
So let's recap on what you have to do:
- Give the sandbox purpose. There has to be a reason for that freedom. If the game is completely linear - event wise - and you have a sandbox, you have failed ROYALLY!
- Your game is not a complete game. You will build it piecemeal over the course of YEARS. Your players will forget you even exist at times. Do not expect people to memorize quests, events, triggers, maze-like room layouts. You need to have a map or a system of navigation. A quest log, hints, etc.
- Do not waste people's time. Do you think it's a good idea to make a grindy game to pretend it's not actually 10 minutes long? Look how well that works out, all of those games get like 2-3 star reviews, even if they are decent. One of my most favorite games on this site is barely hitting 3 stars because of the grind.
- To that end, map markers, room markers, visual indications of where characters are. You have to build all these systems and make sure they work.
- Have progression not be an alcohol induced nightmare. A fever dream of anti logic and magical events that make sense to the developer alone.
- Don't just tell the player what to do, three lines before returning from a scene to the sandbox. Don't just have hints that hold your hand the entire way. But make it so that players that return after a year hiatus are not lost
Honestly there's more I could go on about, but I think that's enough. TL;DR - takes talent, takes work, takes knowing what you're doing. You can't just luck into it. It won't work by mistake, only by design.