Interesting 2D Topdown Shooter games

Games where most of the time is spent shooting things in two dimensional levels from top-down perspective.

Brigador: Up-Armored Edition (link)

The levels are fully destructible. Shield is recharged only by picking up energy from destroyed enemies. Enemies start with shields turned off. When alarm goes off, all enemies raise shield and road blockades are raised until the power plant is destroyed. Enemies notice noise and will investigate its source.

D/Generation (link)

The player has a laser weapon that bounces off surfaces and can trigger switches. They have to get through rooms filled with obstacles and enemies. The player has a limited amount of lives, but can get more lives by rescuing trapped people. Grenades can be found, that can destroy doors and enemies resistant to laser.

Devilish: The Next Possession (link)

The player controls two paddles, which move together horizontally, but the upper paddle can move vertically too and rotate. The screen moves together with the ball and can progress both vertically and horizontally. Besides destroyable blocks, there are also destroyable enemies. Ball can be lost by letting it fly past the paddles or when it gets hit by enemy attacks.

Enter the Gungeon (link)

You go through multiple levels, randomly finding or buying guns and other items. Dying means starting over. Enemies shoot large amounts of projectiles that you have to avoid, dodge with a roll or block with destructible cover.

Foxhole (link)

Massive multiplayer of two factions in a war over large map. Every player controls one soldier. Players have to gather resources, use vehicles to transport them to factories and then transport finished weapons, ammo, supplies and vehicles to the front. In the meantime other players are using these to push the front and fortify new positions.
To shoot you need to aim the weapon. The aiming system has a height component. Standing still and moving the crosshair slowly helps maintain accuracy. Sticking to cover gives further benefits. Players can build trenches and bunkers with AI shooting from it. They have a variety of weapons available including tripod guns, artillery and many different armored vehicles that require more than one player to fully operate.

Galaga Legions DX (link)

Your ship can shoot in any direction. Enemies come in patterns with weak spots. Destroying the weak spots destroys all enemies in the pattern. Sometimes destroyed ships join you.

Galak-Z: The Dimensional (link)

Your ship has forward and backward thrust and has inertia. While engines are on, enemies that are close enough will hear them.

Ghox (link)

Player controls a paddle to deflect balls, which destroy blocks and enemies. The paddle can be damaged, which loses a life. Player can collect temporary power ups and colored orbs. Collecting five of the same color gives permanent bonus. There is also a limited use bomb, that makes the ball split into many more balls.

Lords of War (link)

Each player has a castle that protects shield inside. They can move a guard around the castle that serves as paddle to deflect flying skull into enemy castle, removing parts of the wall. Catching the skull gives mana that can be used to cast spells. When time runs out, the skull gets faster and can't be caught.

Magicka (link)

You have several types of magic which you can combine to achieve various effects and cast them in front of you, at the area around you or on yourself. Effects like damaging or healing beams, bombs, fire walls, shield walls that deflect beams, armor and protection from magic. When multiple people play campaign in cooperation they can combine their beams into more powerful one.

Pop'n Twinbee (link)

Two players play in cooperation and they can throw their partner at enemies and transfer health to each other. Game can be set up, so that enemies prefer attacking one of the players. There enemies in the air and on the ground. The ground enemies have to destroyed by lock on bombs. Upgrades are gained by picking up bells, that change color when shot. The color determines what upgrade the player gets.

Speedball 2: Brutal Deluxe (link)

Players can get score by throwing the ball into opponent's goal and beating up opponents. There are objects on the field which grant bonus score when hit or multiply the score for the next time ball reaches the goal.

Xenon (link)

You have to switch between plane and tank modes to be able to shoot enemies on different height levels.

Honorable mentions

Amnios
Doujin Kaizokuban

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