They are both dark blue shimmers, but are also very different. Catrice has a very subtle shimmer which is electric blue - almost purple. Essence, on the other hand, has more visible teal shimmer. It's not so visible on the photos, since my cameras can't capture the shimmer that well, but they're not so similar in real life. Catrice looks almost purple-ish compared to Essence.
On pointer and ring finger: Catrice It Blue My Mind
On middle finger and pinkie: Essence Hard to Resist
They both apply really well and both need 2 coats for full opacity. If you're still not completely sure about buying Hard to Resist ... I'm telling you: go get it! You can't go wrong, it's only 1,49€ and it's amazing. And if you're one of the lucky people who got It Blue My Mind, keep it safe. It's a real gem.
Thanks for looking and commenting!