So a few weeks ago I was looking for an open source game to port over to NG, and stumbled upon Beats of Rage.
It's originally a DOS/Dreamcast game that happens to be open source (C language). The game isn't great but we're just here for the porting fun.
The base game, for reference:
The engine isn't quite suited for old systems as animations and AI are timing based instead of frame base.
This leads to IA being run 3 to 4 times for each entity each frame (engine operates on 5ms steps).
All the data had to be processed through converter tools to make it usable.
Here's a few progress grabs:
First running minimal build. Can spawn & operate player entity.
Added ennemy entities spawn, AI etc to be able to run the combat layer.
CPU is destroyed by the engine use of floats for coordinates.
Some work later, replaced float coordinates with an integer solution.
Added most entities, BG scrollings, fix layer. Proper conversion and use of level format.
Still missing shadows atm.
At this point the basics are working, most of the remaining work is tedious reworking backgrounds for use on the system.
Engine is "as is" at the moment, except for the exclusion of floats.
Some sprites are unnecessary large, wasting a lot of HW sprites.
Also some entities are showing too much colors and need manual frames adjustments before being able to include them.