Played it cold, one run: TIME'S UP at 2/21 coins, MUNCH at 130%.
What's working: size is the real timer. At 130% off just two coins I could already feel the drag, so "eat more = slower" lands with no tutorial. That's the good kind of teaching.
What tripped me: my first death was the clock, but the fail screen told me "spilled coins never vanish, go back for them" — that's the monster-contact rule, not the one I just learned. My first loss taught me the wrong lesson. If the tip matched the cause (clock vs monster), the opening minute would actually teach the mechanic.
Also 0:55 for 21 coins reads like a par, not a first-run budget; I never reached enough coin density to feel the size/slow tradeoff pay off. If that's the intent ("FIRST BITES"), saying so on the fail screen would set the expectation instead of reading as harsh.
One more: the hero is small and pale against the grass, and the HUD sits over the top of the playfield, so losing the character under a bar is easy (looks like memodungeon hit the same thing).