Halo 5 game ideas: 
A promethean vehicle, called the ripper should be introduced. It has 3 wheels, one front, and two back wheels, and has a hardlight turret that fires streams  of hardlight energy. It takes the same amount of damage as the warthog and has a boost like the ghost making it a quite agile vehicle. It should respawn at the same rate as the  same rate as the warthog. 
Firefight should be more fun.  You get a prize at the end of a set. The more points you have from killing enemys add up to the prize. So, if you have  2500 points you can get a  sniper rifle or something. 
Spartan ops should have a bigger amount of maps. Im tired of the same maps all the time. 
The ranking system should be based on skill. 
Arbiter should return. And if so, I hope 343 can make him playable for some missions like halo 2. 
The boltshot should be weakened down a bit. It’s like a handheld shotgun. 
Plasma rifle, and SMG should return. (Possibly mauler?) 
 They should make a competition. The community has to design their own weapon and armor. The winner gets their designs into the game! I hope 343 reads this, and I hope it helps them! There is still more to come!