fun game, i enjoyed it. my suggestions would be
1. more generators (obviously, its a merge game lol)
2. The enemy to send troops at us.
3. not being able to buy the next level gen. (the current cost of the next level gen is under the max energy)
4. amount of troops depends on energy we have. aka, every troop costs a blank amount of energy and it spawns as many enemies as possible. say troop cost was 100 per troop and you have 500 energy. That's 5 troops. gives strategy of, so do i want to buy troops or generators.
5. more levels. which im sure you were already planning on making.
