Sadly it's very hard to play on a QWERTY keyboard. WASD controls are preferable when you share a game online, because English keyboards are considered the standard layout. If you absolutely want to use ZQSD, you can allow players to also alternately use the arrow keys to move. They will always work regardless of the player's keyboard layout.
That said, I explored a bit and your game seems really solid, with great graphics and solid mechanics!