Oracle : Selecting multiple columns with avg function - oracle

Question

I am trying to display the average values of each player on a row by row basis with the player name
I have looked throughout the oracle docs and previous question asked by other people on stack overflow. I have only come across on how to select average value group by their record id and how to select avg using subquery
For an example,
What i found is to get the average by each row by
select round(avg(g1+g2+g3+g4)) as "Average Score" from ch_user group by playerid;
Do note that i didnt display my PlayerID shown in the picture .
If i were to select player and avg , it will give me ORA-01427. I have tried
select player, (select round(avg(g1+g2+g3+g4)) from ch_user group by playerid) as "Average Score" from ch_user;
But its prompting the error ORA-01427. single-row subquery returns more than one row.
Thank you in advance
UPDATED
I have already found the solution to the problem and i am able to implement it to my query based on #Boneist answer.
However, i find the query long, is there by any chance i could simplify the query ?
My query is
select first_name || ' ' || last_name as Player,game_1 as G1 , game_2 as g2 ,
game_3 as g3, game_4 as G4,total_score as "Total Tournament Score",
round(avg(game_1+game_2+game_3+game_4)) as "Average Score" from ch_user
group by playerid, first_name,last_name,game_1,game_2,game_3,game_4,total_score;

Answer 1

I think you've overthought this... all you need to do is add player into the select list in your first query and add player into the group by:
select player,
round(avg(g1 + g2 + g3 + g4)) as "Average Score"
from ch_user
group by playerid, player;

Answer 2

I think you want to group the data by player_id, but display player name and average. Check if this helps.
select player_name,round(avg(g1+g2+g3+g4)) "Average"
from ch_user
group by player_id,player_name;