Insectonator

Insectonator is a 2D casual Shooter created using Flash and made by BGamesSite. The basic premise is that a backyard is filled with bugs (well, mostly) of various kinds, and the job is to exterminate them... at all costs. There’s only one person who can handle this high-caliber job - you.

Unlock and choose from an assortment of up to 26 different weapons (from the humble beginnings of a rock to the bazooka to the nuke) to exterminate 20 types of insects. Earn up to 28 achievements from accomplishing various tasks such as using certain classes of weaponry to kill the bugs, kill enough, miss enough, etc. Build up your arsenal of weaponry by completing these various achievements.

There are three modes of play: Annihilator, Killer, and Selectioner. The goal in Annihilator is to kill all enemies in the yard. The goal in Killer is eliminate specific insects, in a specific order. The goal in Selectioner is to exterminate a specific group and quantity of insects. With all modes of play, points are earned based on number of enemies killed at once, every bug killed, number of head-shots, and the current kill streak running.

The series continues with Insectonator: Zombie Mode where instead of shooting bugs, you shoot Zombies with a new mode, Don't Touch my gem where you defend your Gem from being taken from Zombies within the time limit and a new variety of weapons like the armor sword and basketball with many other old weapons.

All in all, shoot and blast your way to victory! This game can be played here, and the Zombie mode here

Not to be confused with Infectionator.

Tropes used in Insectonator include:

Anvil on Head: On of the weapons is a falling anvil, and you need to make ten headshots with it to unlock another weapon.
Awesome Yet Practical
BFG: The Mini-Gun with its very high fire rate, very high ammo capacity, and overall large gun size. Crosses onto Awesome Yet Practical categories near the end.
Boom! Headshot!: Possible to achieve in this game, though with increasing amounts of difficulty depending on how big the bug is. In fact, it's also necessary to achieve 170 headshots if you want to gain the nuke.
Catharsis Factor
Gatling Good: Once again, the Mini-Gun.
Kill'Em All: The Nuke. Subverted though, as it only kills all enemies on screen and in the nearest vicinity. Provided that it isn't set in the center of the stage, the enemies farthest from the nuke, will survive the explosion.
Kill Streak: Always present. Though, it resets fairly quickly unless you can keep the streak going. However, once around 20 kills are made in a quick succession, you enter "Inrage" mode - giving you max accuracy for all weapons and never ending until the streak ends. This makes the rifles even more powerful than before.
Shock and Awe: The Lightning weapon.
Sniper Rifle: The Mauser, Dragunov, and Gever.
Squick: You're squashing fairly life-like insects and arachnids, in all the gory detail that implies. If you're put off by "bugs," this game gets pretty gross pretty fast (and you'll likely starting seeing creepy crawlies out of the corner of your eye EVERYWHERE).