Très bon choix

Je pense aussi que Qt/Quick est un bon choix.

Pour le drag and drop que tu utilises beaucoup dans GCompris, j'avais passé un peu de temps avant d'obtenir quelque chose de totalement fonctionnelle.
Je te met le code au cas où :

import QtQuick 2.0
Item {
 width: 800
 height: 800
 id: root
 property int cible: 0
 DropArea {
 id: daCible1
 anchors.left: root.left
 anchors.bottom: root.bottom
 width: root.width/2; height: root.height/2
 onDropped: {
 cible = 1
 console.log("Dans cible 1")
 }
 Rectangle {
 id: reCible1
 anchors.fill: parent
 color: "lightgreen"
 }
 states: [
 State {
 when: daCible1.containsDrag
 PropertyChanges {
 target: reCible1
 color: "green"
 }
 }
 ]
 }
 DropArea {
 id: daCible2
 width: root.width/2; height: root.height/2
 anchors.right: root.right
 anchors.bottom: root.bottom
 onDropped: {
 cible = 2
 console.log("Dans cible 2")
 }
 Rectangle {
 id: reCible2
 anchors.fill: parent
 color: "lightblue"
 }
 states: [
 State {
 when: daCible2.containsDrag
 PropertyChanges {
 target: reCible2
 color: "blue"
 }
 }
 ]
 }
 Rectangle {
 id: reStart
 anchors.left: root.left
 anchors.right: root.right
 anchors.top: root.top
 height: root.height/2
 color: "azure"
 }
 Rectangle {
 MouseArea {
 id: maTuile
 drag.target: parent
 onReleased: parent.Drag.drop()
 anchors.fill: parent
 }
 Text {
 id: teTuile
 text: "Baleine"
 width: parent.width; height: parent.height
 horizontalAlignment: Text.AlignHCenter
 verticalAlignment: Text.AlignVCenter
 font.pointSize: 24
 }
 id: reTuile
 color: "paleturquoise"
 width: root.width/3; height: root.height/16
 anchors.verticalCenter: undefined
 anchors.horizontalCenter: undefined
 x: (root.width - width) / 2
 y: (reStart.height - height) / 2
 Drag.active: maTuile.drag.active
 Drag.hotSpot.x: width/2
 Drag.hotSpot.y: height/2
 states: [
 State {
 when: maTuile.drag.active
 PropertyChanges {
 target: reTuile
 opacity: 0.5
 }
 AnchorChanges {
 target: reTuile
 anchors.verticalCenter: undefined
 anchors.horizontalCenter: undefined
 }
 },
 State {
 when: !maTuile.drag.active & cible == 0
 AnchorChanges {
 target: reTuile
 anchors.verticalCenter: reStart.verticalCenter
 anchors.horizontalCenter: reStart.horizontalCenter
 }
 },
 State {
 when: !maTuile.drag.active & cible == 1
 AnchorChanges {
 target: reTuile
 anchors.verticalCenter: daCible1.verticalCenter
 anchors.horizontalCenter: daCible1.horizontalCenter
 }
 },
 State {
 when: !maTuile.drag.active & cible == 2
 AnchorChanges {
 target: reTuile
 anchors.horizontalCenter: daCible2.horizontalCenter
 anchors.verticalCenter: daCible2.verticalCenter
 }
 }
 ]
 transitions: Transition {
 AnchorAnimation { duration: 500; easing.type: Easing.OutElastic }
 }
 }
}