@Chris Yeah Scorpion Engine seems to be a very fast game engine compared to some older and still develeoped Amiga game engines. And there's some very promising games in developement under Scorpion.
It looks like Scorpion editor is made in Unity, and you don’t find lot source code on there git repo, there is some 68K source code, and it looks like they intend to make boot block games. So these games will have no network support, or P96/CGX support, no AHI support, won’t be true HD install games, only whdload.
On the other side of the coin, the games do play well, they do support AGA. And look like they do support lots of game mechanics features.
(NutsAboutAmiga)
Basilisk II for AmigaOS4 AmigaInputAnywhere Excalibur and other tools and apps.
@Rob As khayoz says, for OS4 there Irrlich Engine, the one of the most powerfull engines of this area : fast, small and opensourced. With gazilion examples, and even big printed books out (you can got them on amazon and anywhere else).
For OS3 such engines of course non-go, as they need resources, so they of course need own os3/68k specific engines where they can support properly AGA, ESC, KS1.3, 68020 with 14mhz and all those things, where every instruction matter.
It's a great idea I hope they go further - in recent years exceptionally clever people have created best in class implementations of beat em ups, shoot em ups, 3D engines (like the new Doom clone), fighting games (like the SF2 tech demo seen on youtube), fast moving platform games (like the Sonic unofficial port), that do things never believed possible - massive numbers of colours on screen, fast AGA 8 plane graphics, massive sprites, real 3D, and there's no reason to have multiple versions of game engines any more when a single platform could provide a toolkit to exploit all this cleverness.