The speaker feels trapped and worn down, and says so plainly. We're told there should be light at the end of the tunnel, a familiar way of promising that hard times will pass. Here the speaker flatly refuses that comfort: "I haven't got light." Life itself is the tunnel, and it seems endless. It's also described as a game that keeps going even when things get tough, so stopping isn't an option.
The one image of the future is bleak: rubble and dust, as if the tunnel collapses rather than opens out. Yet the poem ends on a small, fragile hope. The speaker asks, "Will you be there to catch me before I fall?" and repeats it, "Will you?", which makes it sound less like a question and more like a plea. The short, bare lines keep the mood tired, heavy and exposed, but the final appeal to another person suggests the speaker still wants connection, and maybe help, more than anything else.