Each player sprite is composed with two hardware sprites multiplexed three times so (3x2). An additional sprite is used for the sword and the shirt. The sword sprites are reused when climbing ladders to simplify the multiplexing. The number of animation frames is quite high, so only one direction is stored and the mirrored one is synthesized on the fly in software. The game is 100% C code and as you guessed compiled with Oscar64.
The level of detail achieved with the Oscar64 compiler is incredible. I need to investigate how you manage to multiplex the two top sprites and reuse them two more times. I'm starting a game and I can't seem to reuse the top sprite immediately below it without adding several scanlines. Seeing your game, I realize it's possible, and I'll continue working on it.
Thank you very much for your reply.