To be honest, this year there isn't really anything Halloween-specific going on during the daytime that you can't see or do during the party. In the past there was a Halloween Carnival in the daytime (which was not open during the party), but the Carnival is not happening this year. So if you want to save some money or keep costs down, you might want to just get the MHP ticket. You'll only have 8 hours in the park, but it might be worth it.