to tell you the truth the addition of the weapons was the easy part
that was just adding a few more sprites and ruleset adjustment, which i thought at first was hard, then realized it wasn't so much. (maybe that is why i left it like 90% complete)
However making the game "higher resolution" is really taking a toll :S specifically one feature that i think is the "main" change to vanilla is the merging of the inventory screen and the stats screen. Thanks to a few people I have been able to incorporate a few things already as you can see in the screenshot. And the battlescape inventory is easier since it is just static. The geoscape inventory on the other hand... :O
And to tell you the truth it is far more than i can chew firstly i am no programmer, so if you would like to lend a hand
Secondly i work on it during my "Free time"
In any case I do it because i love this game, anyone can jump in and out at any time, after all the main code is being done by a lot of people so not "many" bug in the code just a matter of passing values and adjusting location of object and assets