head to head
vs
Back to the FuturevsHalf-Life: Alyx
Back to the Future leans Execution (Pure Mechanics); Half-Life: Alyx leans Execution (Pure Mechanics).
Back to the FutureHalf-Life: Alyx
Axis by axis
Execution7 vs 7
Even - both lean on execution about the same.
Reads0 vs 1
Half-Life: Alyx leans harder on reads: Combine and headcrabs scripted.
Variance2 vs 2
Even - both lean on variance about the same.
Optimization3 vs 3
Even - both lean on optimization about the same.
Two games can score the same on an axis and still test it in very different ways - read each rationale, not just the number.