Looking for game that is enjoyable, but still under 10 euros on this sale.

Played lot of rpgs & want to play something else.

Out of games that aren't rpgs I enjoyed/liked well enough:
Nine Parchments
Trine 2
Crusaders Kings 2
Mages of Mystralia
A Hat in Time
The Flame in the Flood
Epistory - Typing Chronicles
Foxtail
Kynseed
Semblance
Shadwen

Games with light/different RPG elements that were awesome
Ghost of a Tale
Tangledeep

ummmm...

Hollow Knight, Dust: an Elysian trail, Spelunky... Good choices if you haven't played any of these.

Stellaris is Crusader Kings in space and it's on sale. Base game is just under 10 € right now. There's still the thunderstorm of DLCs that comes afterwards, though. How familiar are you with point-and-click adventure games? There are dozens you could try that fall under your budget. If you haven't played it, The Secret of Monkey Island defined the genre in the 90s and is still used a reference for every adventure game still released today. But it's not currently on sale, if it matters.

Take a look at Hob.
I've never played Hob but for videos I've seen it seems to have an interesting gameplay.

The STALKER games are on sale, all below €10.

Not on sale, but below €10:
Jagged Alliance 2
Outcast 1.1
Both well worth their full price.

Not into Stellaris, but thank you.

I played Heroine's Quest multiple times, and My brother rabbit & Hero-U.

FTL: Advanced Edition
Civilization III

I think I will keep my money. Thank you guys.

How about a management game? Startopia is a particularly good one.

On this sale? No clue.

On the other hand Ring Runner is always good, and a decent price even not on sale.

Spelunky :)