This is a paid asset, but now you can download 80s Shoot’em Up Kit Free.
Detail this asset from Unity Store: Original Link
80s Shootem Up Kit v1.4
2.0 major update – see changelog
* This template is now C Sharp only *
80s Shoot’em Up Kit is inspired by classic 80s shooters.
This asset provides a clean and complete, mobile optimized, 2D example based on Unity native 2D tools.
Key Features
– Cross-platform, low draw calls, optimized code and assets for mobile devices
– Keyboard, joystick, mouse, and touch screen (drag/buttons) support
– Firing system : shoot delay, bullet count limiter, Auto Fire and fire rate penalty
– Object Pooling example : optimize the application by reusing elements
– Event system : set checkpoint, play or stop an audio clip, spawn an item, change level…
– Level Handling : Encapsulate the whole game in a single Unity scene or handle multiple levels as needed
– + upgrade system, coin items example, several enemy types, cool retro sfx…
– Includes grid helper utility for tile placement