These days, I would approach any commercial engine with caution (unless it is considered one of the industry leaders).
The reason for that is because the market is pretty saturated with game making solutions at the moment, and the effects of that are being felt in the form of a growing number of them either winding up in the graveyard or becoming stagnant (see the Marmalade and Maxplay engines).
Even some of the ones that see initial success will inevitably grow stagnant or disappear altogether (how much do you hear these days of Visual3D.net, 3Dgamestudio, Blitz3D, Darkbasic, Cosmos Creator, Quest 3D, VirTools, ect…)?
darkbasic developer still alive, they just build new product that focus on mobile. new code of course because darkbasic was based on directx.
quest 3d page still say copyright 2012. so i guess that is the year it died.
virtools was bought by dassault - which is a very leading company. probably lived as brand new product now. but it focus more on creating 3d mutlmedia product than 3d engine.
blitz is now open source and free to download. not much commit from what i’ve seen. with a lot of multiplatform open source 3d engine available, blitz is too late.
Dont like being negative about peoples work in realtime as i know hoe BLOODY hard it can be, especialy if your a one man operation (dont think this is, but hey) but have to agree, looks like it was made in 2010.
I started writing my own realtime engine 2-3 years back that i stooped development on after Epic released UE4 (as what was the point after that, especially when was made open source).
Heres some old testing footage, Been thinking about maybe redoing the engine in Vulkan for a test after the recent news on maybe blender 2.8 might aloow adding external realtime viewport engines. Could be fun to get my code boots back on if i could use the work in Blenders viewport
I find Tombstone Engine is fine, it is in source code so it can be improved alot and added some cool stuff like unreal engine, isn’t what for ? Just imagination and creation is then all about it, not only “yeah, it is old so no good” but make it more modern if you like, ok I say positively meh !