Escape Academy

To get this achievement, you need to play online, local multiplayer won't work. You don't need to use the power-ups, just activate the box, grab the item when it opens, and pull the lever to activate again. Rinse and repeat until you get your achievement.

I did this while running through the levels working on getting my wins, most of the rooms usually have a power-up box, so you can run back and forth activating multiple power-up boxes as you play through the levels. Sometimes you can get a master key, which is a one time use item that works for any lock, it was nice to find those and skip some of the puzzles I wasn't a fan of.

I don't know how many times I activated the power-up box playing local multiplayer without ever seeing the achievement. I played a few online matches and got this achievement pretty quickly. To earn any of the achievements from this title update, after loading my save file, I went to the arena in the top right, selected the Tournament of Puzzles pack, then started playing matches.

As the other guide and comments have mentioned, this achievement seems to only unlock through ONLINE play. I would recommend saving this for last as you should hopefully knock out enough power-up boxes if you play ONLINE and grind out the 50 matches. If not, here is a setup that should be easy to use to grind out this achievement.

Setup for grinding:
Friend or 2nd account to IDLE by one of the power-up boxes
Arena - Tomb of the First Escapist (auto-populated)
Game Mode - Scavenger Hunt (I think has the easiest access to the power-up boxes)
Track - See You Later, Excavator (auto-populated)

Complete the puzzles in the 1st room to open to the central area. Make sure you check the power-up box and hopefully, you'll get a master key. If not, it is not a deal breaker and you'll just have to complete the 2 puzzles in the central area. Unlock both doors from the central area and now you should have access to 4 different rooms (starting room, central area, locked room #1, locked room #2). Each of the 4 rooms should have a power-up box available. At this point, you're ready to just grind out the achievement. Keep in mind you can only carry 10 items at a time including keys, puzzle items, attack items, and running shoe(s). Keep the IDLING account by a power-up box so you can dump the attack items on it every cycle or every other cycle. Rinse and repeat until the achievement unlocks.

TL;DR instructions:
1) complete puzzles to unlock central room
2) complete puzzles to unlock the 2 locked rooms
3) keep idle account by a power-up box
4) run to all 4 rooms and use power-up box while unloading attack items on idle account