If the arms aren't annimated, it's best to render them as an imagfe and display them on the HUD. And keep in mind that in most 3D engines a coordinate of 0 along the vertical axis represents the bottom of the screen, while in most 2D engines it represents the top.

EDIT: an other fix would be to open the model of the arms in a model editor (for example Blender), and move it down.

To make sure a project won't die, you have to be motivated to work on it. The way I do this is by switching between level design and programming the engine (this tactic only works when programming games). I first start creating a lot of the engine, untill it can load a simple level. Then when I start to get bored on the engine, I start creating a level. Then I start adding more things to the level, untill I reach a point where something I want to put in it isn't supported by the engine. After designing or improving the level, play it. Then you really see the progress you made, you'll see it a lot better then when you're only working on the engine, and the 'level' consists of only the thing you're working on. When I've seen the progress, I'm moivated again to continue working on the engine. then the cycle repeats and the level gets larger. The level keeps containing everything worked on so far. That way you see how far you have come, and this is what keeps you motivated. And if the engine is almost finished, then you can start creating the levels that will actually be in-game. If your project reaches this stage, you can be almost sure that it won't die before it gets finished.

some other tips to keep you motivated (based mostely on game design)
 - When you start to get bored, play The your game. Don't just test it, but play it. Have fun.
 - show your work to friends. This isn't only good to keep you motivated, but they can also give good comments on how to make it better.
 - When playing other games (or using simular software than the one you're making), look for inspiration. Look at some things and think "I can do that better in my game". Of yourse, don't copy, just look for inspiration, because it's hard to stay motivated on a project for which you have ran out of inspiration.

You can also work open-scource. Then if a project would die (which is still best to prevent), someone else might be able to use parts of it (for example AI, code for a menu, ...) or maybe even continue it. That way all your hard work wouldn't have been for nothing. But still, it's best to keep you motivated and keep working on it.

How do you call them? Do you doB_CALL(_ExampleBCALL)orB_CALL _ExampleBCALLAlso, is your assembler case-sensitive? If so, you might want to check the case. Also, don't forget the underscore at the front of the label.

you can use B_Call($500B) instaed. It's the same.

Make sure the clock is correct. Some computers and routers can behave strange when the clock is wrong, especially when the year is wrong.

I have never tried to reproduce it, but it didn't happen on other doors.

Welcome. I hope you enjoy your stay.

Have some peanuts!

A calc is only 15 MHz (on full speed mode), and you can play reasonable games on it. An arduino also doesn't run the outdated z80, so it should be a bit faster than the calc. Aslo, I noticed the blocks fade away. Is this an effect, or is the screen just really blurry?