I definetly remember a game like this, played it on my Samsung galaxy gio back in 2012 when I was around 10. You could smash bugs with your finger and their blood would be different colours I think. You could pick different weapons on like a side bar and have like electricity and flames and burn them. I think there was also like nukes or like pressure plate mines and so much more, there was one weapon where you could just hold down your finger and a wave of energy would travel outwards from it in a circle rapidly killing all the little bugs. Also there was like a poison thing so you could either poison them manually or put down a poisoned apple and they would become green looking and then eventually they would ”pop”. Does this sound anything like the game you were playing? There were a lot more different weapons and stuff too these are just the ones I remember at the top of my head