- Priming time for each grenade is multiplied ~1.5 times. [The logical explanation would be that it requires more time to properly handle both grenades].
- Accuracy of both grenades is reduced slightly. When the player releases the grenades, the two grenades head off in 2 slightly different trajectories.
- Delay between detonation of each grenade varies from 0.5 to 1.5 seconds.
- Self damage when the grenades detonate is is multiplied 1.5 times per grenade. [The logical explanation would be that shrapnel from the second grenade further worsens the wounds from the first grenade].
Sorry for the funny English... tired right now.