Ideas for clash of clans.
Here are some ideas:
necromancy spell that turns graves into troops.
Small troop like a hamster that doesn't do much damage or have much health but has a chance of dodging a attack like a cannon but the cannon has a chance of missing because of its small size.
base defence test that you can use so you attack yourself (not using your troops/spells up or losing resources from it) to test how good your base would be from an attack.
some troops to have AI to attempt to move away from a bomb when it's set off.
ghost spell that makes troops in the area be able to walk through walls and not set off traps or get attacked until they are out of the spells effect or attacking something.
upgrade spell that makes a troop in it 1 lvl higher so a lvl 2 goblin would go in the spells range and turn into a lvl 3 goblin then turn back to lvl 2 when it gets out of the spells range or the spell runs out.
a troop that will remove graves when it walks on them or does a heal thing (like healer does to buildings when it's defending) on the graves making them go away so the defender doesn't get as much elixir.
monkeys? Like the traps or clan castle when a troop gets to close to a tree there is a chance a monkey could spawn and attack the troop/troops near the tree.
gem barracks that would be like barracks but train some different troops(gem troops) that would cost gems and leave a gem grave that gives you a gem when you clear it like graves giving elixir when you clear them.
Reinforced buildings- you can click a building and use some gold or something to reinforce it so it gets a bit more health but like the traps once destroyed/set off they need to be rearmed(reinforced again)