So, yeah.
You have the Halo world, styles, pace, feel and engine.
You then have the Mass Effect feel, for where you have the ability to travel to different planet, land and interact with whatever is there. Then, once you're done you travel back to the Tower, which is like the Citadel in ways. You can level up, sort you gear out, buy, sell, claim rewards, do pretty much whatever you need to do that is a bot impracticable or impossible when out on a mission or explore.
Borderlands has the great gun and run on a big landscape element to it, which Destiny has in abundance, no more so than when you're teamed up in a Fireteam and taking on enemies. The damage indicators that come off the targets is an obvious feel and works very well, then the Loot system is very similar also, not so in terms of millions of weapons and drops, less frequent but more purposeful when they do occur.
Then you have the 'Gear' which works in a buff way like Skyrim does to suit your class or damage system. Helmets, gauntlets, chest plates, boots, capes and visors. The gear has effect, or rather some of then do, which will buff certain other things, so, for instance, I currently have a set of gauntlets that boost my reload speed when using Scout Rifles. If you use scout rifles, its awesome, if you don't not so much but will still act as armour.
Weapons, LOTS. rifles full autos', semi auto's, snipers, Rocket launchers, machine guns, grenades, powers, the lot.
Then thou have materials, which I don't know what do yet but you collect them and can do something with them that I've not learnt yet.
Then you have your ship, upgrade this to be able to travel further and access farther systems.
Then you 'Sparrow', which in essence is a speeder from Star Wars and lets you get about a lot quicker on the larger more open planets. Which of course, is fully customisable and upgradeable.
I can go on and on and on but really you should give it a few hours at least while the BETA is still up and free.