Hello Dinar87,
-There's sprite issues like when pressing down while midair the character sprite is upside down.
This isn't an issue, it's a recycled sprite and is intended because pixel art is really expensive.
I've left it in for so long because it seemed fun and used the art budget at the time on other animations.
-Some annoying collision issues like the floor sided doors being slightly lower than the surrounding collision blocks meaning you have to jump to get over them
The doors is intended as a workaround to a collision bug in Unity/PhysX where if you have two separate colliders next to each other, even if they're exactly lined up perfectly, other colliders (i.e. the player) will get snagged where they meet, causing them to stop moving.
-cannot aim diagonally
Controls are included in the README.txt located in the .zip bundled with the game, these controls include the keys for diagonal aiming.
They're shown here in the Controls Menu, although I apologize for not expressly naming them "Aim Diagonally Up" and "Aim Diagonally Down". I will include this change in the next update. Should probably remove Inject Tank as well since that's a disabled feature.
Also included in the next update coming soon is automatic diagonal aiming if you hold the left or right movement keys along with up or down.
-moving on the map screen feels bad because of the inverted controls.
If you look at the map tiles, you'll see they follow the controls, they're not actually inverted. Might look that way because of the grid.
-charging animation is not clear when it's finished charging.
This is fair, the next update coming soon has a color tint that flashes on the player to indicate the charging is complete.
Hope you enjoyed the game, and stay tuned for more!