I made a free browser game for people who like Einstein-style logic-grid puzzles ("the gardener with the petunias is in plot C"). Every morning there's a new puzzle in three tiers — beginner (3 categories), intermediate (4), expert (5).
What makes this a bit different from the usual logic-grid sites is that it features Oli the Otter, your problem solving companion!
There's a chat panel where you can ask Oli to check your reasoning, give a hint, or walk through a stuck step. It marks the grid live as it explains.
Free, no signup needed (you can solve as a guest or sign up to save your progress and join the leaderboard).
Today's beginner: https://olilogic.com/?utm_source=reddit&utm_medium=organic&utm_campaign=webgames-launch
Feedback especially welcome on any puzzles or clues that feels ambiguous!