Not sure what you mean by "hardcore games", but I second the Dead Space idea, and I'd say you try Monster Blabe. It's kinda like Monster Hunter Dynamic Hunting, but it's pretty cool. A lot of donate, but it's a challenge to go through stages without it. The same thing is with Plants vs Zombies 2. The second part is also donate-oriented and easy at the start, but the more you proceed, the more often you run into some mad stages where you really want to buy some power up. It's really cool to beat some of those artificially hardened levels.
Or if you're a JRPG fan, try Dragon Quest VIII. It's a complete PS2 port. Just classic!