Ismaila Sarr had Palace ahead before Mohamed Salah found a late equaliser on Liverpool's day of title celebrations.
Afterwards, Glasner said: "I think today I have two feelings: I'm not really pleased with our performance today. A few players I think didn't play how we want to play and this I didn’t like to see. I think that’s why we got the draw because there were so many situations, and we could have won this game.
“I don't forget our start to the season where it was a little bit similar – we missed our chances, we missed our opportunities, because of a little bit of a lack of determination – and this is how I felt today, and that's why I'm not really pleased with today's performance.
“On the other side of course it's an unbeaten end to the season, a point record (in the Premier League for Palace, 53), winning the FA Cup – so a fantastic season overall, and hopefully we learn from this game when we meet for pre-season next year.”
We've not reached out ceiling
On reviewing the season overall, which included winning the FA Cup, Glasner added: “I think we have not reached our ceiling as a team, definitely not, but therefore it needs really hard work and also always being ready to invest in every single training, every single game.
“Now it’s off, now it's not thinking about football for a few weeks, and then we’ll prepare to be ready for the start of the season.
"And then again, I never think about which position we will have at the end of the season or whatever: it's just how can we raise our performance, and again in every single game I can see enough to do.”