Game: OSTRY

OSTRY is one of the most iconic games. It's author has the same name: OSTRY.

= Gameplay = Ostry has various sections: A slide and a PVP arena, Construction and the principal one: Parkour. Looking at the thumbnail, it was made a long time ago.

Parkour
It has a good variety of levels. Each one is really different, and some are absent of Checkpoints. If you complete it, you'll win by reaching the flag.

Slide
A simple construction made with Ice. At the end there's not a flag. You may Press K.

Construction
Enter through teleporters. It's divided into a Cube Gun and a Sky Block section.

Cube Gun
You can build what you want in a terrain, there are no weapons!

Sky Block
You need to build bridges from planet to planet. There's a flag at the end of this minigame.

PvP Arena
This PvP zone has weapons everywhere. Includes some platforms and structures.

= Trivia =
 * OSTRY in general has inspired a lot of players that there are a lot of clones related to this game.
 * OSTRY is actually a Polish word that means "Hard" in English.
 * Also, the word "osrty" has 50 different translations in English.