Five Investigators, And One Very, Very Strange Park.
Thimbleweed Park is a point-and-click adventure game in the style of 1980s adventure game titles such as the Quest series by Sierra. It features puzzles of the same sort, with pixel hunts, inventory puzzles and dialogue aplenty. There are five protagonists, all of whom can interact with each other both to solve puzzles and to change the story.
A dead body is the least of your problems
Thimbleweed Park makes few concessions to modern sensibility: it looks like it would fit in the era it's inspired by, and you only have a to-do list for each character to go by. Most puzzles are fair and intuitive, though a second playthrough will be harder (and occasionally unfair). The game likes to joke, which usually but not always works despite the murder-mystery trappings.
Whether to visit the park
Overall, Thimbleweed Park shows a lot of polish in its graphics, design and presentation, but the story and puzzle gameplay both have a few rough edges that might catch casual players by surprise. It's easy to recommend regardless, both for adventure game buffs and for those looking for casual depth.