You have to use the grenade to jump over that chasm, the landmine sends up while the grenade sends you diagonally, but requires a wall. You don't need to retry it of course, I'm already grateful to you for playing it, just saying cause you seem like you wanted to see more of it ;)
But yeah, the game can be a little difficult but solving it is mostly a puzzle, it's not so much about precision actually. But yeah, thank you for playing my game!