Why this e5 move is excelent when oponent has advange insantly?

https://www.chess.com/analysis/game/live/18870391579?tab=report

I really made a trouble in this game, could not defend. Oponent right from the start started having advantage.

Is this analiser bug? I tried clicking on next moves suggested by analizer after this e5 move but many moves passed and could not win and often white was getting advantage.

For me now it looks like its a blunder -  I am just giving pawn for free. 

The move e5 was not the best. It should have cost you about .69 of a pawn-- if you had followed the suggested line with Bg4 and f6. Instead, you dropped your knight too. Nxe5 was the big mistake. That's why Nxe5 is colored orange.

Moves are described as :

• Best
• Excellent
• Good
• Inaccuracy
• Mistake
• Blunder

The moves described as "excellent" are not the best but they are not as bad as blunders.

The computer rates moves based on the change in evaluation it sees.

I agree that "Excellent" is a problem as a description since the move immediately leads to the loss of material in this case.  Maybe the descriptions need to be changed slightly. 

The old descriptive notation words of questionable and dubious should be brought back.

3...e5? is a mistake indeed: you lose a pawn.

The premise of assigning a hierarchy to moves is flawed at lower "depth".

Reason being is that engines start calculating lines and provide an "evaluation" by giving a number.

At lower depths (for a simple path) and a quick analysis, the engines don't have enough time (a second or two, but sometimes less) to find or "weed out" some of the inferior positions.

Given more time, evaluations (and the changes between them) will also change.

This doesn't change what "book" move results can be given.

This might not (but can) change what "blunder" and other results (missed win, etc) can be given.

So, with lower depth (little time) at best...

It's a blunder checker and leaving opening book checker.

If you want more than that, use self analysis and perhaps the unlimited option.

Okay, so here's what I think is wrong.

3. e5, This looks good but it doesn't work. 1 thing I would definitely start doing if I were you is count how many pieces attack the square before offering a trade there.

Also 5. f6, yes it does kick the knight but it weakens your king too much. It blocks your knight and makes castling hard.

I'm not trying to ruin your chess, not at all, but if you take this into consideration you can definitely be a stronger player.

I misspoke here

If you try making alternative moves during the analysis you can get other results like "excellent" or "best" when they can be (but may not be) book moves.

This shows how engines are not great at openings. You can waste a lot of time on this, and even more using the site engine and analyzing 5 or more lines (even on your own device).

A better approach would be to find out why e5 wasn't good and what other options you might (might not) want to consider...like Bg4/Bf5/Nf6 and why.