It's likely either VT09 or some derivative of VT369, but I could not determine the specific mapper. It's definitely strange; it contains VT03 games that are converted to VT09 format, something I've never seen before on another console. I attached two VT09-converted game extracts below (with Thin Ice having its copyright restored).
As a side note, does anyone know what this chicken-ish sprite set is at the start of the ROM? It's heavily overwritten (whatever it is), but I don't recognize it as a game.