A 4-1 win at relegated Plymouth saw the Os finish seventh and one point shy of the play-off places.
"I thought we were good enough to finish ninth or 10th and I told the chief executive that," said Slade. "We were good enough for the top 10 and next season - with the right signings in the summer - we can push on again.
"Traditionally my teams don't start that brilliantly, even the year I got into the play-off final with Yeovil I didn't have a great start.
"It`s always nice to finish the season with a win, particularly after the disappointment of losing to Tranmere at home last week.
"You would probably prefer it the other way around if you had a choice to be honest, but that's the way it has panned out."
Source: PA
Source: PA