Developer SonicMastr has published a port of the Godot Game Engine, compatible with the PS Vita.

What is Godot for PS Vita?

From the Godot Readme:

Godot Engine is a feature-packed, cross-platform game engine to create 2D and 3D games from a unified interface. It provides a comprehensive set of common tools, so that users can focus on making games without having to reinvent the wheel. Games can be exported with one click to a number of platforms, including the major desktop platforms (Linux, macOS, Windows), mobile platforms (Android, iOS), as well as Web-based platforms (HTML5).

SonicMastr has adapted the Godot editor to generate PS Vita vpk files, based off of Stary2001 (responsible for the Switch homebrew port of Godot) and EIREXE Contributions utilizing PVR_PSP2. This is the full Godot Editor with PS Vita support, based on Godot 3.x.

Running the compiled games will require a hacked PS Vita, which should be no problem currently.

PS Vita Godot Requirements/Limitations

The developer notes the following requirements to build PS Vita vpk files:

• Any LiveArea assets HAVE to be 8-bit indexed AND have to be the sizes listed. Otherwise VPK installation will fail
  I like to use pngquant
• Version HAS to be in XX.YY format. If it is not, it will be defaulted to 01.00 to protect from failed installations
• Parental Level has a range of 0 (off) to 11 (adult). Anything above or below will default to 0
• Always change the Title ID from default if planning an actual release to avoid overwriting other applications
• Logging can be viewed by using PrincessLog
• Make sure you enable fallback to gles2 no matter what (for now, need to fix this or it probably already is. I’m too tired)
• OSX build hasn’t been tested. Just Windows and Linux

Can I port my existing Godot Games to PS Vita with this?

From the developer:

As long as the godot games have a pck file, are made with a 3.x version before 3.5-rc5, only use base godot features, and support GLES2, then it should be portable

SonicMastr also notes that Mono (.Net) support is not possible currently on the Vita

Download Godot for PS Vita

You can download the editor on the developer’s github here.

Source: SonicMastr