Darkcraftia

I'm trying to figure out what libraries to use with Ruby. Once i find one i need to see how to make a window that can be re-sized around for the players perfect fitting. I'm trying to figure out for build 1 on how the screen would look like while there's a basic GUI menu that would show:
>Health(More health can be obtained by having amour on)
>Resources Tab(Recourse's used to protect yourself from oncoming monsters by the day)(Examples of what would be built: Traps, Barriers, Workstation's, Weapons, etc)
>Ammunition tab(Shows how much ammo you have of the specific weapon that you are carrying)
>Inventory screen(Maximum of space: 25)
>Character Tab(Shows your stats and how much money your holding, Your name, Age)(Optional: Your crew name(if found survivors).

Health is recovered by 1 every 2 minutes while in the resting position or eating food which can recover a random amount of health. Health can be extended by having amour on which can have a different amount of health depending on what the stats it can have. Armour can lose its durability from how much damage it can take or from anything else that can affect how it can handle damage.

Money can be used by the small villages/towns that are still alive from the monsters that are attacking which would attack on random days by a single group or a army that can take them all down. Money can be obtained from looting homes that have been left alone or from anywhere that has a chest, locker, etc. Money can be used to buy new amour, amour repair, weapons, ammunition, resources, tools, food, or anything that will help you to survive.

Resources can be used to make barriers, traps(most traps that can be built for start are pitfalls or a small turret that can shoot 1 bullet every 10 seconds). Your resources can be collected by gathering it from the wild, dropped from monsters that can be carrying a small or big amount of it. Can be bought from villages/towns that can have resources in stock for sale or any NPC's that might be willing to sell some that they may have laying around there.

Traps will help you defend your small base that is a small wooden house. Your house be upgraded but will take time to build, the same for building your traps. Building can take a small amount of resources and a time to build, a pitfall would take these resources(10 wood planks, 5 hours of labor)(tools required: Shovel, Hammer). Building can be very improving to make your traps much better by how it would react from a movement, your house can be upgraded from a wooden house to a metal bunker that can withstand hordes of monsters but if there's enough protection to help out.

Ammunition can be looted from homes that have been left alone, loot able objects, bought from any NPC's that sell any. Ammunition is very important for you to defend yourself and your crew(if made) from monsters. If ammunition has ran out and unable to find any than the other choice you can use would be to use melee weapons but that can drain away how much stamina you can use.

I might have a decent idea for a 2D game(or bad). If anyone wants to provide tips or advice if i should go ahead with this or change around the idea a bit more to make it related for a RTS, or a TBS. If you have anything that might help me to code this will be much help since im still learning on how to use Ruby and OpenGL