What are some games you like that you would consider to be easy/lack a lot of depth in their mechanics?
What’s funny about this question is you assume there is a link between those two things. Easy ≠ lack of depth. In an objective sense, there’s absolutely no relationship between those things. The range of scenarios that can be produced has no relevance to how hard it is to produce a successful outcome.
As relevant to players though: a game that has a large objective depth will only have a large relative depth if it is at the right level of difficulty. Right meaning hard enough that players have to utilize everything available to them and engage with all the depth that is there, but not so hard that only a small selection of solutions are viable.
For example, a game that is about pressing a button as many times as possible within a minute. This game doesn’t have much depth compared to nearly any other game (like chess lets say, or checkers, or getting a good time in a racing game). However it’s inhumanly hard to press that button 1000 times in a minute.
Call of Duty is hard on veteran, that doesn’t mean it’s a particularly interesting game. I had this difficulty in writing the review for Thi4f, the game is legitimately really really hard with all the custom difficulty settings turned on. Some of my level solutions were downright arcane. This isn’t interesting though, because levels consist of repeating the same dumb thing until it works basically. There’s no room for improvisation or significant problem solving, the levels aren’t even nonlinear enough to give you an alternate means to pass through them. I had a similar issue playing through Super Meat Boy, that I did not have playing mario, contra, megaman, or ninja gaiden. I felt in super meat boy that I was just repeating the same small selection of inputs again and again until I got every part right rather than acting in the moment. It felt like there was only really one or two ways to beat the levels, and that was lame.