First steps in Hiveswap
After the first cutscene, you will get to the protagonist's room. There are a few items there, which you can collect or use.
The first one are the shoes, hanging right next to the door. You can grab them and take them with you. They're highlighted on the picture above.
Next, take some things from the bed. Click the pink toy and the game will zoom in. Take the two keys.
Then, there's the walkie-talkie on the floor. It has no batteries, but take it with you regardless.
Go to the left to see the other part of the room. You can click the window to see what's happening outside.
You'll find a diary lying on a shelf next to the TV. You can use the silver key to open it. Just click the key and then the diary. You will be able to read through it or write a new entry.
Talking through the walkie-talkie
Open the wardrobe to get the batteries. You'll find a toy there, from which you can obtain the batteries. Place them in the radio by clicking the batteries and then the radio. This will allow you to talk to the brother. You will be able to select some answers, but they don't change anything.