I don't know if it is a hot take or not but I definitely see it in a lot of comments giving feedback . Someone posts a trailer asking for feedback and I see comments like "what is your unique hook? Every mechanic you showed in the trailer I've seen in other games."

The keyword in my statement is "small":

Your SMALL indie game doesn't need a unique hook (or mechanic)

Small vs Large Game

It does make sense to me that a player would think "why would I play this game when I've played something I know I like that is very similar" if it is a game that costs $20+ or you know you would be investing 40+ hours in it. Also for games you can play indefinitely - MMORPGs, Multi-player FPS, sports games, etc - because there you are trying to persuade them to stop playing their current game to play your game.

As a player, lets say I see a game for $2.99 that is like 6 hours of gameplay, I'm not thinking "why should I play this game instead of other games similar to it" - I have enough time and money to do both. It isn't either/or.

Often times when I get done playing a game I love I end up looking to see if there are any games similar to it. If they are small (time and money) indie games (just because I am quicker to throw dollars to support an indie) I usually will give them a try. It is like a piggyback sale.

The most likely for me to not enjoy it is because the game isn't well done - something is lacking; something wasn't implemented very well - not because I'm thinking oh I have seen this all before, nothing is new here.

Not at all unique examples

It doesn't always have to be new or unique to be fun. People replay old games all the time. People are still making solitaire and blackjack games, and people are still downloading them.

I also think of this video - How to Survive in Gamedev for Eleven Years Without a Hit (YouTube) - I haven't watched it in a while but I remember him making card or puzzle games and reskinning them for holidays - things that don't seem to have a unique hook.

Unique Mechanics

Unique mechanics help keep the game fresh. As other new elements are introduced in the game - new enemy types, other new mechanics/powers, new environmental elements - the player is interested to see how the unique mechanic works with these. The interest from the mechanic being unique, meaning there isn't a set expectation.

Short game means less of a need to keep the game "fresh" - which having a completely unique mechanic could be overkill, as there are other ways to do that.

Player onboarding: for a short game, I want to get in and start playing, not learning. Using familiar mechanics helps players get into it right away.

If not very intuitive, a player may not want to learn or master a completely unique mechanic. There needs to be a payoff for the time spent mastering it - as in, its not great for the game to end right after mastering it.

Enough...

Enough rambling, would love to hear your thoughts on it.

TL;DR - For small, low-commitment games, it seems like players just care if it is fun, not unique. Larger games need to differentiate because players have to choose between games.

*Note: to be clear, I'm not saying make more clones, re-skins, slop, etc - the point is basically the opposite: put focus into quality instead of differentiation