My Favorite part is working on filling up the Database section. Its fun to work with Database elements and plan Classes, Skills, Gear, Enemies, Afflictions etc. Its also fun to plan the Story for the Game. However, Due to lack of Resources, I find myself gathering all the resources first and then planning a Story around it.
I love to create new heroes and try to give to them the best personality by using pictures, I also try to pay a lot of attention to the details during mapping, so to think the best way to use the shadow etc..
Character creation and writing out cutscenes are my favorite part about making an RPG! Building the world, writing interactions, having a splash of lore even if the game is super short... and of course, whilst testing a game can have some unfun aspects about it, I enjoy testing cutscenes over and over to hear the voice acting applied!
Parts that are my least favorite definitely has to be setting walking routes when eventing (lots of counting squares on the grid), cutting voiced lines 'cause it's so tedious... leveling the voices isn't so bad, since in RM, I can do that in internally rather than externally, which I usually do in my VNs on another engine. BUT! Since voice over is lower and the default audio is always SUPER LOUD, the part I really, really dislike the most when doing a new RPG is internally leveling all the game sounds I am going to be using. All the system sounds, specified animations I will use a lot (gets really tedious when dealing with which animations are used in what skills, etc.) Ugh.... that's the most painful part in my opinion. Luckily I was smart with my one map challenge project, lowering everything beforehand, so when I added voices to the build later, I could just focus on voice leveling and ignore SFX for once lol.
That aside, overall, I love the game making experience, even the longsuffering of the boring and tedious parts, because when your game is done, you feel so accomplished!
That moment where I open up the game for testing, try out a new feature I implemented or event I created, and having it work just how you want it to. It's extremely satisfying.
As for my favorite specific part, it has to be writing out story events and NPCs. I love breathing life into a world. Mapping is probably my least favorite thing to do, but designing the map itself is pretty fun. Having to actually put everything together can be a pain for me. haha
It depends on the game. With platformers, the level design was easily my favorite part. Creating new levels the players could travel through was very fun. That still applies to RPG design, but I really enjoy filling out the database with skills/weapons/items/etc. You have progress that's easy to see once you're done for the day.
Due to a situation in which I thought plugin adaptations had stopped for the QPlugins, I "ghetto" converted these 7 over yesterday. They appear to work perfectly as long as you use old style plugin commands. I am uncertain if I will have a lot of free time in the future to work on this, but if you'd like them, here they are.