I have a pretty simple idea for a rpg
The idea is each player would start out with 2-6 powers from the supperpower wiki (exact amount depends upon potantcy of abilities) and would gain more for accomplishing various tasks , or killing other players.
I am wondering two things 1. How much intrest is there for a game like this
2. What kind of mechanics should I use for how the powers interact.
3.if this is too complicated for my first time being a gm
Well then, since you asked, here comes my humble opinion. Dis/regard at your own leisure. ;3
1: Existing interest is relative - by making a game interesting enough, you can plainly create interest among bay12 by yourself. I'd actually say that "super/natural power" is somewhat of an established trope, so what kind of plot you build around it, would be the more important point.
2: I'd advise to keep it simple. Like, a character only being able to be affected by ~2 effects at once. If another, new effect, comes along, just make a save roll for the existing one/s, possibly according to the "potency" stat of the caster/s.
3: How complicated it becomes, really depends on yourself. Again, less is more. To give a - somewhat - exaggerated example; If you plan to roll each round for 1. Initiative 2.Hitchance 3.Dodgechance 4.Damage-range 5. Blocking/Resistance 6. Bonus effects, that netts you 12 rolls per round for a single attack, from 2 combatants. As soon as there is a larger scale battle with npc's, like a 4v4, or four players doing "their thing somewhere", that translates into a whooping ~44 rolls for each round. That is tedious, especially as it is, indeed, only a somewhat exaggerated example.
Seeing as you are playing with the pvp thought, Initiative might stay in 1. Hit / Dodge, also; 2,3. And the damage-range, for which a crit is only applied on a natural max roll, 4. There is also the possibility of taking the difference between hit and dodge, and to use that for the damage-range... but, really, just rolling it is easier in my book. So, 8 rolls for each round of combat.
All in all, if you are unsure if this could be too tedious for you, maybe trying with 3 players, but no more than 4 should do the trick. Starting, that is - you can always expand further at a later date.