Shadowdark's gameplay loop is a shining example of design done right. It's hard to find a better and tighter gameplay loop in tabletop gaming today. In contrast, D&D often leaves players feeling confused as they spend 30 minutes sorting through combinations of actions, burning bonus actions, and dealing with conditional 'this doesn't count as action X, so I can do Y afterward' situations.
The 5E gameplay loop of D&D is not just in need of fixes, it's in dire need of major overhauls. From the damage per round to monster hit points, these issues are deeply ingrained in the rules and demand immediate attention. Only a new edition could effectively address them, and the time for that is passed when D&D had the chance to introduce a new edition.
Some 5E clones do a little better and clean things up, while some of the 2024 D&D decisions make it worse. The 30-minute turn needs to die, that is, one-sixth of a 3-hour session for one player on one turn. Even 5 minutes is too much. And this gets worse as the characters' level increases.
Shadowdark makes exploration turn-by-turn, limits actions per turn, and puts a real-time ticking clock on the action. You don't need to spend a lot of time on a turn deciding, nor should you want to. The "best thing to do" is based on the player's imagination and will mainly be apparent given the situation on the table.
I still play 5E, but that tight gameplay loop with the timer solves many problems.
This tight gameplay loop also enhances accessibility. A new player will be on an equal footing with a more experienced player. D&D has this "hidden knowledge" where new players will feel like they will "suck" next to players who know all the tricks. Shadowdark's tighter gameplay loop levels the playing field and puts imagination before rules and book knowledge. There is still "experienced player knowledge," but it leans closer to practical "in-game wisdom" than knowing a rule or exploitable combo.
The gameplay loop is more straightforward to describe to new players. People understand, "move and do an action," and when it is their turn, they know they can do these things. No other player at the table will try to marginalize them or push them to the back because they are more talkative or outgoing. I have seen this happen, especially in the theater of the mind games! Some of the more shy players get "pushed to the back of the party" by the louder and more aggressive players at the table, and neither side knows they are doing it. Shy players carry backpacks and torches, while the more outspoken players are in the front, having all the fun and solving problems.
As a referee, I had to constantly fight that and ensure everyone had a chance to play, but table dynamics tended to return the game to that state after a while. Shadowdark fixes the problem by making the combat and exploration turn structure the same. It is your chance to go, outgoing or shy player, what will you do?
The clock is still running; choose wisely and choose quickly.