A couple free & open-source Engines and game frameworks you can use today as alternatives. Feel free to comment with more.
Godot - https://godotengine.org
MonoGame - https://www.monogame.net/
FNA - https://fna-xna.github.io/
SDL - https://www.libsdl.org/
SFML - https://www.sfml-dev.org/
Adventure Studio - https://www.adventuregamestudio.co.uk/
bgfx - https://github.com/bkaradzic/bgfx
armory3d - https://armory3d.org/
ogre3d - https://www.ogre3d.org/
Renpy - https://www.renpy.org/
thanks for all the suggestions so far, I went through all comments (I hope) and gathered them here on a github list so it's easier to share around, feel free to make PR with more things or corrections. There are both free and license based tools on that list now, but all by suggestions so far.
https://github.com/DJLink/list-of-game-engines-and-frameworks/
@djlink Defold, Solar2D, Phaser, Love2D
@djlink I'm a big fan of RogueEngine - https://rogueengine.io/
It uses ThreeJS to make building 3D browser games easy (and it's very Unity-esque UI makes it easier to swap over)
@djlink I guess it's time to check out Godot for real... We released many games on XNA back in the day, but we need the tools of a proper engine, at this point.
@somepx with I could write longer posts XD, thanks for sharing
@djlink I'm sorry to be THAT person but ogre insist in the fact that is not a game engine or game framework but a rendering engine. It seem to be a really important distinction for them.
@YoSoyFreeman bgfx as well, why I mentioned frameworks too. Many people sometimes just want something for rendering, why I shared
@djlink hi there :) I'm gonna throw my open source engine framework DOME into the pile: https://domeengine.com
@djlink Another option I don’t see on the list is GDevelop - https://gdevelop.io/
@djlink
Unreal Engine
Roblox Studio
@djlink @grahamboree Don't forget Cute Framework! https://randygaul.github.io/cute_framework/#/
@djlink Thing is most of those don't offer what Unity does: being able to compile for almost any gaming platform: PC, mobiles, consoles, web... which is huge! I would love to make things in Löve, but it's just not the same, from a commercial perspective. And it's a pity :'(
@playmedusa that is true, but some of them people have been able to port it to consoles, it’s not out of the box but at least there’s a way. Not ideal but Unity is becoming far from ideal as well :(
@ima fixed, thanks
@djlink I saw some people talking about Heaps (and Haxe), but I can't really vouch for it so I didn't bother with a PR.
https://heaps.io/
@djlink pixi.js
@djlink May I suggest also https://ncine.github.io/ for multiplatform 2D games?
@djlink some #Python #FLOSS #gameDev
- #pygame https://pygame.org
- #pyxel https://github.com/kitao/pyxel
- #Ursina https://www.ursinaengine.org/
- #panda3d http://panda3d.org
(Updated to add panda3d, thanks @entikan)
And, why not add, you can make games with #py5 too! https://py5coding.org
@djlink Also some engines have docs specifically for onboarding Unity devs:
Stride https://doc.stride3d.net/4.0/en/manual/stride-for-unity-developers/index.html
Flax https://docs.flaxengine.com/manual/get-started/flax-for-unity-devs/index.html
Godot 3 https://docs.godotengine.org/en/3.1/getting_started/editor/unity_to_godot.html
Even some that don't use C#:
Unreal https://docs.unrealengine.com/5.0/en-US/unreal-engine-for-unity-developers/
@djlink Hello David
I think you forgot to list ORX Engine (2.5D - Open source - Data driven)
https://www.orx-project.org/
Adding it to the GitHub list even few days later would be great <3
@djlink
UPBGE and RangeEngine