Tunnel Defense is the cross-chain mini-app, $CTM routes only. It is a fixed-action game, not a volume game: every scored operation is the same size and pays the same, whatever the route and whatever you hold.
Tunnel Defense opens later in the season, with Phase 2.
What counts
An eligible operation moves exactly 10 CTM between two different supported networks, and leaves the value on the destination chain for at least 24 hours. Only the first 12 operations a day score. Same-chain transfers never score.
Moving your own funds across chains is eligible. That is exactly what the product is for.
Reaching a supported destination chain for the first time pays a one-time bonus, once per destination, per account.
What one operation unlocks
Beyond its p8ints, a single confirmed operation satisfies the cross-chain leg of qualification, and counts as one of the five real actions that lift your multiplier cap. 
