I find this position to be ingeneous. It has an "I wonder how many of these things I miss OTB" quality to it, as it appears likely to have occurred in a game.
It is a white to move and win, not a forced mate.
I should mention that my comment after black's 1st move is too strong, as he does have 1...Qxb2+ etc, but the principle holds. It is not an extremely difficult puzzle, but I find there are so many possibilities that simply swap material and only one that simply destroys black.
There is another possibility which is 1. Qf4 Rd6 2. Qxf6 a5 3. Rxd6 cxd6 4. Qd8+ Ka7.
Correct. Rd6 delays mate as well, and the pattern still works for white.
A nice trick, though I wouldn't say ingenious. The key is to recognize that it's effectively a fork, as though the queen is protected, here she would be better left without a recapture! Thus you have a double attack on c7 and f6.
But like you said, it's one of those things that could easily go completely missed in an OTB game; what we all need is a huge arsenal of patterns like these so we can recognize that f6 is essentially hanging in a flash, just like how we can pretend that certain squares that seem covered might not be at all if they are guarded by a pinned piece. Ideally, we want stuff like that to be just as obvious as knowing how a bishop moves, which I presume most of us forget about 0% of the time.