Cosmic Express

essentially a set of line tracing puzzles. Very tough, but possibly the most ridiculously satisfying game I've played when I actually find a solution. It's a strong test of your spatial reasoning, if you're trying to solve things via trial and error and drawing paths randomly you're going to hit a wall and end up unsatisfied. You need to be able to think things through and figure out the order that particular points need to be visited. The levels are quality not quantity, there's a decent number but not a ton, but every single one poses a unique challenge. Some of the later puzzles took me hours to solve, but the feeling of finally figuring them out made me feel like a million bucks. The postgame puzzles eventually hit a point where they feel like they're for super-experts, and I eventually hit a wall where the amount of time a puzzle was taking simply wasn't worth it. But prior to that point, it was a great time, and I absolutely got good value out of it.