-grenade explodes but dose not make brake blocks. -fire grenade explodes in fire blocks. -crystal grenade explodes in a shower of crystal shards that if touched hurt the enemy. -water grenade explodes in water blocks. -sticky grenade sticks to walls and anything above you explodes. -gas grenade explodes in gas that can make your enemy's sleep or get sick or choke. -acid grenade explodes in acid melts some blocks. -electric grenade explodes and electrifies any enemy's that are close. -black hole or worm hole grenade that will make a black hole or a worm hole that will suck in enemy's if there close. -E.M.P.grenade stops any electric item,robots,blocks,vehicles or weapon's.
All of these are good ideas! With the acid grenade I would hope that some blocks like valuable rare ore/material blocks are resistant to the acid because I would hate to find a small rare vein of some extremely valuable material and accidentally hit that vein with an acid grenade while defending myself from an oncoming, attacking creature.
That would require lot of work. I would be fine with just grenades exploding and dealing non-block affecting damage of different types as well as demolition charges for destroying most materials.
There should even be mini black hole or worm hole grenades that are difficult to make and are rare. They could suck up enemies if they were close enough to the explosion radius.