The people who wrote Death Squared must have played quite a bit of Portal. (If you’ve not played Portal, where have you been? It’s a series of fiendish puzzles which are overseen by a nasty computer with a great line in one liners).
Death Squared uses a similar scenario (you have to perform a series of tests for some reason) but the actual tests themselves involve each player getting their coloured cube from the start position to the end position. Each level involves a lot of experimentation, and it works really well the more people you have. Two player is rather good, three player for us was hampered by the need for one player to control two cubes. The puzzles are nicely progressive and really encourage the players to work together. Nowhere near as frantic or silly as Overcooked (of which more later), but fun for thinkers who want some cooperative action.